Unit 21 · U.S. History: World Wars and the Cold War

In 1908 a new car cost more than most families earned in a year. By the mid-1920s a Ford Model T sold for under three hundred dollars, and a factory worker could buy one. Henry Ford did it with the moving assembly line: instead of a team building one car, the car moved past workers who each did one small job over and over. A Model T that once took more than twelve hours to build could be finished in about ninety minutes. The car remade the country. It needed paved roads, gas stations, motels and suburbs, and it let a farm family drive to a city they had never seen.

Most people still could not pay cash for a car, a washing machine or a radio. So businesses sold on installment credit: a small payment down, then monthly payments with interest. Buy now, pay later. By the end of the decade a large share of cars and household appliances were bought this way. Credit made the boom bigger, because families could spend money they had not earned yet. It also made the boom fragile. If wages fell or jobs vanished, the payments would still come due.

Radio arrived almost overnight. Station KDKA in Pittsburgh began regular broadcasts in 1920. Within a few years, families across the country gathered around a wooden set in the parlor to hear the same music, the same ballgames and the same advertisements at the same moment. For the first time a farm family in Illinois and an apartment in New York could share one national experience. Advertising on radio taught Americans to want the same products, which fed the consumer economy even more.

Not everyone shared the good years. Farmers had borrowed to expand during World War I, when Europe needed American grain. When European farms recovered, prices for corn and wheat collapsed, and farmers spent the whole decade in debt. Coal miners, textile workers and most Black Americans in the rural South saw little of the boom. The 1920s were roaring mostly in the cities and mostly for people with wages to spend.

In 1922 a young cornet player named Louis Armstrong took a train from New Orleans to Chicago to join King Oliver’s band on the South Side. Chicago’s Black population had more than doubled during the Great Migration, and the clubs along State Street were packed. The music they played was jazz: fast, built on improvisation, rooted in blues and ragtime. Records and radio carried it to white audiences across the country. By the end of the decade jazz was the sound of the age, and the age took its name from it.

In New York, the neighborhood of Harlem became the center of a movement in writing, painting and thought that came to be called the Harlem Renaissance. Langston Hughes wrote poems in the rhythm of blues. Zora Neale Hurston collected the folk stories of the Black South. Writers and artists argued about what it meant to be Black and American at the same time, and they insisted that their own lives and voices were worthy subjects of art. Their work reached readers far beyond Harlem and shaped American literature for the rest of the century.

At the same time the country tried to stop drinking. The Eighteenth Amendment, in force from January 1920, banned making, selling or transporting alcohol. Supporters, many of them churchgoers and reformers, expected less crime, healthier families and safer workplaces. Prohibition did cut drinking for a while. But millions of people kept buying liquor from illegal bars called speakeasies, and supplying them became a huge criminal business. In Chicago, gangs led by men like Al Capone fought over the trade, and the city’s violence made national headlines.

By 1933 most Americans had decided the experiment had failed. Enforcing the law was expensive, courts were clogged, and the money flowed to criminals instead of taxpayers. The Twenty-first Amendment repealed Prohibition that December. It remains the only amendment ever passed to cancel another one. Prohibition is worth remembering as a test of a hard question: when a law tries to change how millions of people live, what makes it work or fail?

The same decade that produced jazz also produced a wave of fear. Between 1890 and 1914 millions of immigrants had arrived from Italy, Poland, Russia and other parts of southern and eastern Europe. Many older Americans saw them as too Catholic, too Jewish, too poor or too radical. This attitude is called nativism: the belief that people born in the country deserve more than newcomers. After a Communist revolution in Russia in 1917 and a string of bombings in 1919, the fear turned to panic. In the Red Scare of 1919 and 1920, the government arrested thousands of suspected radicals and deported hundreds without trial.

Congress answered with the Immigration Act of 1924. It set a quota for each country, tied to how many people from that country had lived in the United States decades earlier. The effect was deliberate: large quotas for Britain and Germany, tiny ones for Italy and Poland, and none at all for Japan and most of Asia. Immigration from southern and eastern Europe fell sharply. The law stayed in force for forty years, and it later shut the door on many people fleeing Nazi Germany.

The Ku Klux Klan of the 1920s was different from the terror group of Reconstruction. Refounded in Georgia in 1915, it sold itself as a patriotic club for white Protestants and recruited with paid organizers and modern advertising. Its enemies were Black Americans, Catholics, Jews and immigrants. At its peak in the mid-1920s it claimed millions of members and had real political power, especially in Indiana, Oregon and Colorado, not just the South. Klan members held parades in daylight, elected mayors and governors, and marched down Pennsylvania Avenue in Washington in 1925.

The Klan collapsed almost as fast as it rose. In 1925 Indiana’s Klan leader was convicted of the rape and death of a young woman, and members quit by the hundreds of thousands. The 1927 trial and execution of Sacco and Vanzetti, two Italian immigrant anarchists convicted of murder on thin evidence, showed the same fear at work in the courts. Historians read the 1920s as two Americas pulling against each other: one urban, diverse and modern, the other rural, Protestant and frightened of change.

Through the late 1920s stock prices rose so fast that people who had never owned a share started buying. Many bought on margin: putting down as little as ten percent and borrowing the rest from a broker. If a stock went up, the buyer kept all the gain. If it went down, the broker demanded the loan back at once. By 1929 the market was a tower of borrowed money. Prices had little to do with what the companies actually earned. That is speculation: buying not because a thing is worth the price but because you expect someone else to pay more.

On Thursday, October 24, 1929, prices broke. Panicked selling on the New York Stock Exchange overwhelmed the tickers. A group of big bankers pooled money to buy stocks and calm the floor, and it worked for a day. On Tuesday, October 29, the selling came back and nothing could stop it. Sixteen million shares changed hands. Brokers called in margin loans; investors who could not pay were wiped out, and their forced selling drove prices lower still. By mid-November the market had lost roughly a third of its value.

Only a small minority of Americans owned any stock, so why did the crash matter to a farmer in Illinois? Because the economy underneath was already weak. Farm prices had been falling for a decade. Wages had not kept up with what factories produced, so warehouses were filling with unsold cars and radios. Wealth was concentrated at the top, and the middle had been spending on credit. When the crash destroyed confidence, families stopped buying, factories cut shifts, and the credit chain began to snap link by link.

Economists still argue about which cause mattered most. Was it the debt, the unequal incomes, the mistakes of the Federal Reserve, or the collapse of trade after new tariffs in 1930? What they agree on is that the crash turned a slowdown into a depression, a long period in which production, jobs and prices all fall together. It would last, in one form or another, for more than ten years.

By 1932 the numbers were beyond anything the country had seen. About one worker in four had no job at all, and many more worked only a few days a week. In Chicago the city could not pay its teachers for months. Families who could not pay rent were evicted, and on the edges of cities people built shacks from scrap wood and tin. They called these camps Hoovervilles, after the president. Men rode freight trains looking for work. Breadlines stretched around blocks. In the countryside, farmers watched banks foreclose on land their families had worked for generations.

Herbert Hoover was not a do-nothing president, and he was not a cruel man. He had organized food relief that fed millions in Europe after World War I. But he believed deeply that direct government payments to individuals would weaken people’s character and that recovery had to come from business. He urged companies to keep wages up and asked charities and local governments to care for the needy. By 1931 charities and cities were out of money. In 1932 Hoover signed a law creating the Reconstruction Finance Corporation to lend money to banks and railroads, hoping it would trickle down to workers.

The summer of 1932 broke what was left of his reputation. Thousands of World War I veterans, many with their families, camped in Washington to ask Congress to pay a bonus they had been promised for 1945 early. They called themselves the Bonus Army. The Senate said no. In July, Hoover ordered the Army to clear them out. Soldiers with tanks and tear gas burned the camp. Newsreels showed veterans being driven from the capital by the army they had served in. Hoover’s defenders said the order was to clear only downtown; the public saw a president attacking the poor.

In November 1932 Franklin D. Roosevelt, the governor of New York, beat Hoover by a landslide, carrying forty-two of forty-eight states. Roosevelt had promised a New Deal for the American people but had been vague about what it meant. Four months passed between the election and the March inauguration. During those months the banks began to fail in earnest, and the country waited.

On Sunday, April 14, 1935, the sky over the Oklahoma and Texas panhandles turned black in the middle of the afternoon. A wall of dust thousands of feet high rolled across the plains, and inside it people could not see their own hands. Cars stalled, chickens went to roost at noon, and families stuffed wet rags under doors. People called it Black Sunday. A reporter’s phrase for the region stuck: the Dust Bowl.

The dust was not just bad luck. For fifty years farmers had plowed up the deep-rooted grass that held the soil of the southern Plains in place, planting wheat when prices were high during World War I and the 1920s. When a severe drought began in 1931 and lasted most of the decade, the bare topsoil dried to powder. The constant plains wind did the rest. In the worst storms, dust from Kansas fell on ships in the Atlantic Ocean. Children and old people died of dust pneumonia. Fields that had grown wheat grew nothing.

Hundreds of thousands of people left. Many headed west on Route 66 toward California, and whatever state they came from they were called Okies, rarely as a compliment. In California they found low wages in the fields, camps by the roadside and signs telling them to keep moving. Dorothea Lange’s photographs for a federal agency, especially a 1936 picture of a worn mother with her children, showed the rest of the country what the migrants’ lives looked like. Historians use those photographs as evidence, and also ask how the photographer’s choices shaped what viewers felt.

The federal government responded with science. The Soil Conservation Service, created in 1935, taught farmers to plow along the contour of the land, leave stubble in the fields and plant rows of trees as windbreaks. The government also bought up some of the worst land and returned it to grass. When the rains came back at the end of the decade, the plains recovered, though the region’s water and soil remain fragile. The Dust Bowl is a case study in how human choices and nature together can make a disaster.

Franklin Roosevelt took office on March 4, 1933, with the banks collapsing, and he moved faster than any president before him. He kept Congress in session for what became known as the Hundred Days. Fifteen major laws passed. The Emergency Banking Act let sound banks reopen under government inspection. The Glass-Steagall Act separated ordinary banking from stock speculation and created the FDIC, which insures deposits so that a bank failure no longer wipes out savings. Bank runs of the old kind essentially stopped. That insurance still protects your savings account today.

Roosevelt did not follow one clear theory. He called it bold, persistent experimentation: try something, and if it fails, admit it and try something else. Some programs paid people to work. The Civilian Conservation Corps put young men in camps planting trees and building trails in state and national parks, including in Illinois. The Public Works Administration built dams, schools and bridges. Others paid people not to produce. The Agricultural Adjustment Act paid farmers to leave fields empty so crop prices would rise, which meant plowing under crops while people went hungry.

The National Recovery Administration tried to end cutthroat competition by having each industry write codes setting prices, wages and hours. Businesses that signed displayed a blue eagle in their windows. The Tennessee Valley Authority, a government-owned company, built dams that brought electricity and flood control to one of the poorest regions of the country. Never before had the federal government run a business, hired the unemployed by the million or told farmers what to plant.

Roosevelt explained all of it on the radio. His fireside chats, delivered in a calm, plain voice as if he were sitting in the listener’s living room, made millions feel that someone in Washington understood their lives. The chats are a lesson in communication. He explained what a bank does, why gold was leaving the country, what the new laws would try. Historians credit the chats with rebuilding trust as much as any law did.

In 1935 Roosevelt turned from emergency measures to programs meant to last. The Works Progress Administration, the WPA, became the largest employer in the country. Over eight years it hired millions of people, at wages set below private jobs so it would not compete with them, to build roads, airports, schools and parks. It also paid writers to record oral histories, artists to paint murals in post offices, and actors to stage plays. Many Chicago schools, bridges and park buildings from the 1930s are WPA work, and the stone stamp is still on them.

The Wagner Act of 1935 gave workers a legal right to form unions and bargain with employers, and it created a board to police unfair labor practices. Union membership tripled by the end of the decade. Then came the law Roosevelt considered his most important. The Social Security Act created old-age pensions paid for by a tax on workers and employers, insurance for the unemployed, and aid for the disabled and for poor children. For the first time the federal government promised that growing old or losing a job would not mean destitution.

The law had deep flaws, and they were not accidents. To win the votes of southern Democrats, Congress left farm workers and domestic servants out of the pension system. Those two categories held most Black workers in the South, so the promise did not reach them for decades. Women who worked in the home were covered only through husbands. Historians point to this as an example of how a reform can advance and exclude at the same time.

The New Deal also changed politics. Black voters, who had voted Republican since Lincoln, moved into the Democratic Party because relief programs, imperfect as they were, reached them. Union members, immigrants in the cities and farmers in the West joined them. This New Deal coalition elected Democrats for most of the next thirty years. Roosevelt himself won four elections, the only president to do so, and after his death the Constitution was amended to limit presidents to two terms.

Not everyone cheered. Business leaders and conservative Democrats formed the American Liberty League in 1934 to argue that the New Deal was destroying free enterprise, piling up debt and giving Washington powers the Constitution never granted. Many newspapers, including the Chicago Tribune, attacked Roosevelt daily. These critics argued that the government could not spend its way out of a depression and that regulations were keeping business from hiring. That argument has never stopped; you will hear versions of it in every election today.

The attack from the other side was louder and, to Roosevelt, more dangerous. Senator Huey Long of Louisiana, a brilliant and ruthless politician, said the New Deal had done nothing for the poor. His Share Our Wealth plan promised to take fortunes over a few million dollars and give every family a house, a car and a yearly income. By 1935 his clubs claimed millions of members, and he was planning to run for president. He was assassinated in September of that year.

Father Charles Coughlin, a Catholic priest in Michigan, drew tens of millions of radio listeners with attacks on bankers that turned, over time, into open hatred of Jews. Dr. Francis Townsend, a retired physician in California, proposed a pension of two hundred dollars a month for everyone over sixty, to be spent within thirty days. Millions of older Americans signed his petitions. Each movement showed how much pain the New Deal had not touched, and each pressed Roosevelt to do more, which helps explain Social Security and the higher taxes on the rich in 1935.

Reading these critics fairly matters. The right was correct that the New Deal expanded federal power far beyond anything in the past and that the debt grew. The left was correct that unemployment stayed high and that many of the poorest got little. Roosevelt’s answer was that a democracy in crisis had to act, and that acting imperfectly beat not acting at all. Historians still weigh those claims, and so should you.

The Wagner Act gave workers a right on paper. Making it real took a fight. The old American Federation of Labor organized skilled workers by craft and had little interest in the millions of unskilled workers on assembly lines. In 1935 John L. Lewis of the United Mine Workers broke away to form what became the CIO, the Congress of Industrial Organizations, which organized every worker in an industry, skilled or not, Black or white, into one union.

The breakthrough came in Flint, Michigan. On December 30, 1936, workers at a General Motors plant stopped the line and refused to leave the building. A sit-down strike meant the company could not bring in replacement workers without physically removing the strikers, and removing them risked wrecking the machines. The men slept on car seats while their wives and supporters passed food through the windows. Police tried tear gas and were driven back. After forty-four days General Motors, the largest corporation in the world, recognized the union in February 1937. Auto workers’ wages and conditions changed for a generation.

Steel was harder. Chicago’s Republic Steel refused to sign. On Memorial Day, May 30, 1937, strikers and their families held a picnic and march near the plant on the far South Side. Chicago police opened fire on the crowd. Ten marchers were killed, most shot in the back or side, and dozens more were wounded. A newsreel camera recorded it. A Senate committee later concluded the police had used far more force than the situation called for. The Memorial Day Massacre is a Chicago event that belongs in every account of American labor.

By 1941 union membership had roughly tripled since 1933, and the CIO’s steel and auto unions were among the strongest institutions in working-class America. Unions raised wages, shortened hours and built the middle class of the postwar decades. Employers argued that they also raised costs and slowed change. The right to bargain collectively, and the limits on it, remain live questions in Illinois today, from teachers to warehouse workers.

The Constitution gives judges the last word on whether a law is allowed, and in 1935 and 1936 the Supreme Court used it. It struck down the National Recovery Administration, unanimously, ruling that Congress had handed lawmaking power to industry codes and had reached into local business the Constitution left to the states. It struck down the farm program too. The justices, most of them appointed by earlier Republican presidents, read federal power narrowly, as courts had for decades. Roosevelt believed they would strike down Social Security and the Wagner Act next.

Fresh from a landslide re-election in 1936, he proposed in February 1937 to let the president appoint an extra justice for every justice over seventy who did not retire, up to six new seats. He said it would help elderly judges with their workload. Everyone understood the real purpose: to pack the Court with judges who would uphold the New Deal. The reaction shocked him. Newspapers, Republicans and many Democrats called it an attack on the independence of the courts and on the separation of powers. His own vice president opposed it. The bill died in the Senate that summer.

And yet Roosevelt got most of what he wanted. In the spring of 1937, while the fight raged, one justice began voting with the liberal side, and the Court upheld a state minimum wage law, the Wagner Act and then Social Security. Whether the justice switched because of the pressure is still argued; some evidence shows he had shifted before the plan was announced. Over the next four years retirements let Roosevelt appoint seven justices. The Court that emerged accepted broad federal power over the economy, a reading that held for the rest of the century.

The episode is a lesson in checks and balances. The Court checked the president and Congress. Congress and public opinion checked the president when he tried to bend the Court. And elections, over time, reshaped the Court anyway. Proposals to change the size of the Supreme Court have come back in recent years from both parties. The 1937 fight is the precedent everyone cites, and it is worth knowing what actually happened.

Did the New Deal work? Judge it by the numbers and the answer is mixed. Unemployment fell from about twenty-five percent in 1933 to about fourteen percent in 1937, then jumped again when Roosevelt cut spending to balance the budget. Full employment came only with World War II, when the government spent on ships and planes at a scale that dwarfed anything in the 1930s. Some economists say this proves that spending works and the New Deal was simply too small. Others say it proves that private investment, not government, creates lasting recovery. The same evidence supports two arguments.

Judge it by what it built and the answer is clearer. Deposit insurance, Social Security, unemployment insurance, the minimum wage, the right to unionize, rules for the stock market, rural electricity and thousands of schools and bridges all date from these years. Before 1933 the federal government touched most people’s lives through the post office. After 1941 it was in their paycheck, their bank and their old age. Americans came to expect that Washington would act when the economy failed. That expectation itself is the New Deal’s largest legacy.

The debate over the role of government has never closed. One side argues that markets, left alone, correct themselves and that government programs cost more than they deliver, create dependence and pile up debt for the next generation. The other argues that markets can fail catastrophically, that individuals cannot insure themselves against a whole economy collapsing, and that a democracy has both the power and the duty to protect its people. Each side has strong evidence from the 1930s, and each has weaknesses it prefers not to discuss.

You will meet this argument again in 2008, when banks collapsed and the government spent hundreds of billions to stop the fall. It returned in 2020, when a pandemic shut the economy and Congress sent checks to nearly every household. The people arguing then were, knowingly or not, arguing about the New Deal. Knowing what actually happened in the 1930s is the best equipment for judging the next version. What was tried? What worked? What did not?

In 1934 a Senate committee spent months investigating why the United States had entered World War I. Its conclusion, that bankers and arms makers had pushed the country toward war for profit, was too simple, but millions believed it. More than a hundred thousand Americans had died in a war that seemed to have settled nothing. Between 1935 and 1937 Congress passed a series of Neutrality Acts that banned selling arms or lending money to any country at war. The idea was that if the United States sold nothing and owed nothing, it could not be dragged in again.

Meanwhile the world was coming apart. Japan invaded China in 1937. Adolf Hitler, who had taken power in Germany in 1933, took Austria in 1938 and Czechoslovakia in 1939. On September 1, 1939, Germany invaded Poland, and Britain and France declared war. By June 1940 France had fallen and Britain stood alone, bombed nightly. Roosevelt believed the United States could not stay out, but a large isolationist movement, led by figures like the aviator Charles Lindbergh and strong in the Midwest, argued that America should defend its own hemisphere and nothing more. The Chicago Tribune was the movement’s loudest newspaper.

Roosevelt moved step by step. In 1940 he traded fifty old destroyers to Britain for naval bases and pushed through the first peacetime draft in American history. In March 1941 Congress passed Lend-Lease, which let the president lend weapons and supplies to any country whose defense he judged vital to the United States. Roosevelt compared it to lending a garden hose to a neighbor whose house was on fire. Over the war Lend-Lease sent about fifty billion dollars in aid, mostly to Britain and the Soviet Union. By the fall of 1941 American warships were escorting convoys and being fired on by German submarines.

In a January 1941 speech Roosevelt described a world worth fighting for, one built on four freedoms: of speech, of worship, from want and from fear. He was preparing the country for a war it had not yet entered. Historians debate how far he led public opinion and how far he followed it. What is clear is that in November 1941 most Americans still hoped to stay out, and one Sunday morning ended that hope.

Japan and the United States had been on a collision course for years. Japan’s leaders wanted an empire in East Asia and the oil, rubber and metals of Southeast Asia. The United States, which supplied most of Japan’s oil, cut off those shipments in the summer of 1941 to force Japan out of China. Japan’s military decided that if it was going to seize the oil of the Dutch East Indies it had to first cripple the American fleet based at Pearl Harbor, Hawaii. Talks in Washington continued while a fleet of six aircraft carriers steamed east in silence.

Just before eight on Sunday morning, December 7, 1941, the first wave of about one hundred eighty Japanese planes came over the mountains of Oahu. The American battleships were moored in a row. Within two hours, the attackers had sunk or badly damaged eight battleships and destroyed most of the aircraft on the island’s airfields. About twenty-four hundred Americans were killed, nearly half of them on the battleship Arizona, which exploded and sank with more than a thousand men aboard. Japan lost twenty-nine planes. By luck, the American carriers were at sea and untouched.

The next day Roosevelt asked Congress to declare war, calling December 7 a date which will live in infamy. The vote was nearly unanimous. Three days later Germany and Italy, Japan’s allies, declared war on the United States. The isolationist movement dissolved overnight; Lindbergh asked to fly combat missions. The country that had argued for two years about whether to fight was now at war on two oceans against three powers, with an army smaller than Portugal’s had been a few years earlier.

Pearl Harbor also raised questions that historians still study. Why was the fleet caught by surprise when American code-breakers were reading Japanese diplomatic messages? The answer, most conclude, was not conspiracy but ordinary failure: warnings that were vague, sent too slowly or read by the wrong people. The attack taught a lesson that shaped American policy for the rest of the century. Never again, leaders decided, would the country be unprepared or wait for the enemy to strike first.

The United States won the war partly with a weapon no other country could match: its factories. In 1939 American plants built a few thousand military aircraft. By 1944 they built almost a hundred thousand in a single year. Ford built a plant at Willow Run, Michigan, that turned out a four-engine bomber roughly every hour. Shipyards on the West Coast launched cargo ships in weeks instead of months. By the end of the war the United States had produced more weapons than all the Axis countries combined. Roosevelt called it the arsenal of democracy.

This did not happen by itself. The War Production Board, a federal agency, told companies what to make and what they could not make. No new cars were built for civilians from early 1942 until the war ended; the auto plants built tanks and planes. The government set prices, froze many wages and rationed scarce goods. Every family got ration books with stamps for sugar, coffee, meat, gasoline and shoes. Drivers had a sticker on the windshield showing how much gas they could buy. Americans grew vegetables in victory gardens and collected scrap metal and cooking fat for the war.

The war was paid for two ways. Taxes rose sharply, and for the first time most working Americans paid federal income tax, taken out of their paychecks. The rest was borrowed by selling war bonds to the public, with movie stars and schoolchildren leading the drives. Federal spending rose to about ninety billion dollars a year, ten times the level of the late 1930s. The Depression simply ended. Unemployment fell below two percent. Wages rose, and with little to buy, families saved.

The war also moved people. Millions left farms and small towns for jobs in Detroit, Los Angeles, Seattle and Chicago, which became a center of aircraft engine and munitions production. Hundreds of thousands of Black southerners came north in a second Great Migration. Mexican workers came under a program called the bracero agreement to fill farm jobs. Crowded cities, housing shortages and racial tension followed; in Detroit in 1943 a riot killed thirty-four people. The home front was not always united.

About sixteen million Americans served in the armed forces during the war. Someone had to build the planes. Between 1940 and 1945 the number of women in paid work rose by roughly six million, to about nineteen million, and for the first time married women and mothers went to work in large numbers. They welded ship hulls, riveted bomber wings and ran drill presses. The government and the press celebrated the figure of Rosie the Riveter, a strong woman in coveralls with her sleeves rolled up. Posters told women that they could do it.

The reality was more complicated than the poster. Women were usually paid less than the men they replaced. Many employers hired them reluctantly and expected them to leave the moment the war ended. Child care was scarce; the government funded some centers, but most working mothers relied on relatives. Black women, who had mostly been limited to domestic work, fought for and won factory jobs, often in the least pleasant departments. Still, the paycheck and the skill were real. Many women said later that the war was the first time anyone had treated them as capable of serious work.

Women also served in uniform. About three hundred fifty thousand joined the women’s branches of the Army, Navy, Coast Guard and Marines, mostly as clerks, mechanics, nurses and radio operators. About a thousand women flew military planes as ferry pilots and trainers in the WASP program, delivering aircraft from factories to bases so male pilots could go to combat. Thirty-eight of them died. They were considered civilians and were not granted veteran status until 1977.

When the war ended, the factories laid women off first to make room for returning soldiers, and government messages switched to urging women home. Most of the gains in factory work vanished within two years. Yet the share of women working never fell back to prewar levels, and the daughters of the Rosies grew up knowing what their mothers had done. Historians see the war less as a revolution than as a crack in the wall, one that the women’s movement of the 1960s would widen.

After Pearl Harbor, fear and old racism toward Asians on the West Coast combined into demands for action. Newspapers, politicians and some generals claimed that Japanese Americans might help an invasion, though no evidence of sabotage was ever found. On February 19, 1942, Roosevelt signed Executive Order 9066, which let the Army declare military zones and remove anyone from them. The Army used it against one group only. About one hundred twenty thousand people of Japanese ancestry living in California, Oregon, Washington and Arizona were ordered out. About two-thirds were American citizens by birth.

Families were given days, sometimes a week, to settle their affairs. They could take only what they could carry. Farms, shops and homes were sold for a fraction of their value or simply lost. People were first held at racetracks and fairgrounds, sleeping in horse stalls, then moved to ten camps in remote deserts and swamps from California to Arkansas. The camps had barbed wire, guard towers and barracks with no privacy. Schools, newspapers and baseball leagues sprang up inside, run by the prisoners themselves. Most stayed for about three years.

The government called it evacuation and relocation. The people inside, and most historians now, call it incarceration: imprisonment without charge or trial. In 1944 the Supreme Court upheld the removal in Korematsu v. United States, ruling that military necessity in wartime justified it. Three justices dissented. One wrote that the order fell into the ugly abyss of racism. Another warned that the ruling was a loaded weapon that any future government could pick up. Decades later the government admitted that the Army’s claim of necessity had rested on false statements.

Meanwhile thousands of young men from the camps volunteered for the Army. The 442nd Regimental Combat Team, made up of Japanese Americans, fought in Italy and France and became one of the most decorated units of its size in American history. In 1988 Congress formally apologized and paid twenty thousand dollars to each surviving prisoner. The episode is studied as a test of what the Constitution means when a frightened country decides that one group is the enemy.

The Allies agreed that Germany, not Japan, was the greater danger and had to be beaten first. But the biggest share of the fighting in Europe was done by the Soviet Union, which Germany had invaded in June 1941. On the Eastern Front, millions of soldiers fought along a line a thousand miles long. At Stalingrad, in the winter of 1942 to 1943, the Soviets surrounded and destroyed an entire German army. Roughly eight of every ten German soldiers who died in the war died fighting the Soviets. Stalin demanded that the Americans and British open a second front in France, and for two years they were not ready.

Instead the western Allies started at the edges. American troops landed in North Africa in November 1942 and, after early defeats, learned how to fight. They took Sicily in 1943 and pushed slowly up Italy against fierce resistance. Meanwhile American and British bombers attacked German cities and factories day and night. The bombing killed hundreds of thousands of civilians, and historians still debate how much it shortened the war. It did force Germany to pull fighters and guns back from the front to defend its cities.

The second front finally opened on June 6, 1944: D-Day. Under General Dwight Eisenhower, about one hundred fifty-six thousand American, British and Canadian troops crossed the English Channel and landed on five beaches in Normandy, France, in the largest seaborne invasion in history. At Omaha Beach, Americans came ashore under machine-gun fire from cliffs and took thousands of casualties in a single morning. By nightfall all five beaches were held. Within weeks a million Allied soldiers were in France. Paris was freed in August.

Germany struck back once, in December 1944, through the forests of Belgium in the Battle of the Bulge, the largest battle the U.S. Army fought in the war. American troops held, at a cost of about nineteen thousand killed. In the spring of 1945 the Allies crossed the Rhine from the west while the Soviets fought into Berlin from the east. Hitler killed himself on April 30. Germany surrendered on May 8, 1945, celebrated as V-E Day, victory in Europe.

For six months after Pearl Harbor, Japan won everywhere. It took the Philippines, where about seventy-five thousand American and Filipino prisoners were marched sixty-five miles with little food or water in the Bataan Death March, and thousands died. It took Singapore, the Dutch East Indies and islands across the Pacific. Then in June 1942 the Japanese navy tried to seize the tiny American base at Midway. American code-breakers had read the plan. In a single day American carrier planes sank four Japanese aircraft carriers. Japan never recovered the initiative.

The Pacific war was fought over water on a scale hard to imagine, and it was fought for islands, some no more than a mile long, that could hold an airfield. The American strategy was island hopping: seize the islands that mattered, bypass the rest and let their garrisons starve. Guadalcanal, Tarawa, Saipan, Iwo Jima, Okinawa. Each landing meant Marines wading ashore into gunfire from bunkers dug into coral and volcanic rock. Japanese soldiers were ordered never to surrender, and almost none did. On Iwo Jima in early 1945, about seven thousand Americans died to take eight square miles.

The fighting was marked by hatred on both sides that historians have called a war without mercy. Japanese forces committed atrocities against prisoners and civilians across Asia. American propaganda showed the Japanese as animals, and some American troops killed prisoners and took body parts as trophies. Meanwhile Navajo Marines used their own language as an unbreakable code, and Black units and Mexican American soldiers fought in a military that was still segregated.

Okinawa, from April to June 1945, was the worst. About twelve thousand Americans died, along with roughly a hundred thousand Japanese soldiers and a similar number of Okinawan civilians, many of whom were forced or persuaded to kill themselves rather than surrender. Japanese kamikaze pilots deliberately crashed planes into American ships. Planners looking at an invasion of Japan itself, scheduled for November 1945, expected casualties far beyond anything yet seen. That expectation shaped the decision you will read about in the next section.

From the moment Hitler took power in 1933 the Nazi government stripped German Jews of their rights, their jobs and their property. After the war began, Germany’s conquests placed millions more Jews under its control. Beginning in 1941, special units shot Jews by the hundreds of thousands in Eastern Europe, and in 1942 Germany built camps designed for killing. At Auschwitz and five other death camps in occupied Poland, trains arrived daily and most passengers were murdered in gas chambers within hours. By 1945 about six million Jews had been killed, along with millions of others: Poles, Soviet prisoners, Roma, disabled people, and gay men. We call this the Holocaust.

How much did Americans know? A great deal, and earlier than many later claimed. Reports of mass shootings reached newspapers in 1941 and 1942. In late 1942 the State Department confirmed a report that Germany planned to kill all the Jews of Europe, and the Allies publicly condemned it. But the news was often buried on inside pages, and many readers found it hard to believe. Before the war, the strict immigration quotas of 1924 kept most Jewish refugees out. In 1939 the ship St. Louis, carrying more than nine hundred Jewish refugees, was turned away from the United States and returned to Europe, where about a quarter of its passengers were later murdered.

The official position was that the fastest way to save the Jews was to win the war. Requests to bomb the rail lines to Auschwitz were refused as a diversion of resources, even though American bombers hit factories a few miles away in 1944. Officials in the State Department delayed rescue proposals and, in some cases, hid information. Only in January 1944, after Treasury officials documented that delay in a report to the president, did Roosevelt create the War Refugee Board. It helped save perhaps two hundred thousand people, largely in Hungary, proof of what earlier action might have done.

In April 1945 American troops reached camps like Ohrdruf, Buchenwald and Dachau and found the dead and the dying. General Eisenhower ordered soldiers, reporters and members of Congress to see it so that no one could later claim it had not happened. The Holocaust is studied as the extreme case of what a modern state can do, and America’s response as a lesson about what a democracy owes to strangers in danger. The questions it raises are still argued whenever refugees ask for shelter.

In 1939 scientists who had fled Nazi Germany learned that German physicists had split the uranium atom. Albert Einstein signed a letter to Roosevelt warning that Germany might build a bomb of unimaginable power. Roosevelt started a small research program. After Pearl Harbor it became the Manhattan Project, run by the Army under General Leslie Groves with the physicist J. Robert Oppenheimer leading the weapons laboratory. It would cost about two billion dollars, employ well over a hundred thousand people, and remain secret from nearly all of them. Most workers never knew what they were building.

Chicago’s role came first. Fermi’s pile under Stagg Field proved on December 2, 1942, that a controlled chain reaction was possible. That was the foundation for everything else. Huge plants were built in secret at Oak Ridge, Tennessee, to separate the rare kind of uranium that could be used in a bomb, and at Hanford, Washington, where giant reactors modeled on Fermi’s pile produced a new element, plutonium. At Los Alamos, New Mexico, scientists designed the bombs themselves. Vice President Harry Truman, who had chaired a Senate committee on war spending, was told nothing until he became president in April 1945.

On July 16, 1945, in the desert of New Mexico, the first atomic bomb was tested. The explosion was brighter than the sun, and the blast was felt more than a hundred miles away. Oppenheimer later said a line from Hindu scripture had come to him: he had become death, the destroyer of worlds. Germany, the original reason for the project, had surrendered two months earlier and had never come close to a bomb. The weapon would now be used, if at all, against Japan.

Some of the Chicago scientists objected. In June 1945 a group led by James Franck sent a report arguing that using the bomb on a city without warning would start an arms race with the Soviet Union and cost the United States the world’s trust. They proposed a demonstration on an empty island instead. Their report was set aside. A generation later some of the same scientists founded a magazine in Chicago whose cover carries a clock showing how close the world stands to catastrophe, a warning that has never been retired.

On August 6, 1945, a single American plane dropped a uranium bomb on the city of Hiroshima. The blast, the heat and the fires destroyed most of the city in seconds. About seventy thousand people died that day, and tens of thousands more died from injuries and radiation sickness by the end of the year; the total is usually given as more than a hundred thousand. On August 9 a plutonium bomb fell on Nagasaki and killed at least forty thousand more. On the same day the Soviet Union, keeping a promise to the Allies, declared war on Japan and attacked its army in Manchuria.

On August 15 Japan’s emperor announced surrender by radio, the first time most Japanese had heard his voice. The formal surrender was signed on an American battleship in Tokyo Bay on September 2, 1945. The war was over. In the United States the news brought crowds into the streets. Most Americans, and most soldiers waiting to invade Japan, believed the bomb had saved their lives, and polls at the time showed overwhelming approval.

Historians have argued ever since, and the argument turns on evidence. The case for the decision: Japan’s leaders had rejected surrender demands, Okinawa showed what an invasion would cost, and even after Hiroshima the Japanese cabinet was deadlocked until the emperor intervened. The case against: Japan was already blockaded and starving, some Japanese leaders had been seeking peace through the Soviets, the United States refused to say whether the emperor could stay, and the Soviet attack may have mattered as much as the bombs. Some historians add that Truman also wanted to impress the Soviet Union. There is evidence for each claim, and no document settles it.

What is not in doubt is what the bombs did. The survivors, called hibakusha in Japanese, suffered burns, cancers and stigma for the rest of their lives, and many of them spent those lives telling the world what they had seen. The United States has never used a nuclear weapon since, and neither has anyone else, but nine countries now have them. The question the Chicago scientists asked in June 1945 became the central question of the next fifty years.

When the shooting stopped, the world had changed shape. Britain and France were exhausted. Germany and Japan lay in ruins under occupation. China was sliding into civil war. Only two countries came out stronger: the Soviet Union, with the largest army in the world and control of Eastern Europe, and the United States, whose factories were untouched and whose economy produced about half of everything made on earth. The United States alone had the atomic bomb. These two powers, allies for four years, would soon be enemies for forty.

Roosevelt had died in April 1945, but his plan for the peace went forward. In June 1945 fifty countries met in San Francisco to sign the charter of the United Nations, an organization meant to succeed where the League of Nations had failed after World War I. Its Security Council gave the five main victors, including the United States and the Soviet Union, a veto over its actions. Unlike 1919, the Senate approved American membership overwhelmingly. Trials at Nuremberg put surviving Nazi leaders before an international court for war crimes and crimes against humanity, setting a precedent that still shapes international law.

At home, Congress had planned ahead. The Servicemen’s Readjustment Act of 1944, known as the GI Bill, offered every returning veteran money for college or job training, low-interest loans to buy a home or start a business, and a year of unemployment pay. About eight million veterans used the education benefit. Colleges that had served the wealthy filled with the sons of factory workers and farmers. Home loans built the suburbs. Economists count the GI Bill among the best investments the government ever made.

The bill’s promise was not equal. It was administered locally, and in the South, and often in the North, Black veterans were steered away from colleges, denied loans by banks and shut out of new suburbs by rules that barred Black buyers. About a million Black Americans had served. Their exclusion from much of the GI Bill’s wealth is one root of the gap in family wealth that persists today. The war made the United States a superpower and built its middle class, and it left the question of who belonged to that middle class for the next generation to fight over.

The wartime alliance broke apart within two years of victory. The Soviet Union had lost more than twenty million people to a German invasion and wanted friendly governments on its borders. By 1947 it had installed Communist regimes across Eastern Europe, and Winston Churchill said an iron curtain had fallen across the continent. American leaders saw a dictatorship expanding as Hitler’s had. Soviet leaders saw a rich rival with the atomic bomb building bases around them. Each side read the other’s defense as aggression. This standoff, fought with money, spies, weapons and words but never directly with armies, is called the Cold War.

The American strategy took its name from a diplomat named George Kennan. Writing from Moscow in 1946, he argued that Soviet power could not be talked out of expanding but could be contained: blocked firmly wherever it pushed, until the Soviet system changed or collapsed from within. In March 1947 President Harry Truman asked Congress for four hundred million dollars to help Greece, where Communists were fighting a civil war, and Turkey, which the Soviets were pressuring. The principle he announced, that the United States would support free peoples resisting takeover, became the Truman Doctrine. It committed the country to a global role it had rejected in 1919.

Western Europe was still in ruins, and hunger and unemployment were feeding Communist parties in France and Italy. In 1948 Congress approved Secretary of State George Marshall’s plan to send about thirteen billion dollars in aid to rebuild European economies. The Marshall Plan was offered to the Soviet Union and Eastern Europe too, but Stalin refused and forced his satellites to refuse. Within four years Western European production was above prewar levels. Historians count it among the most successful foreign policies in American history, and note that it also created customers for American goods.

Not everyone agreed. Some conservatives argued that the country could not afford to rebuild the world. Some on the left, including Roosevelt’s former vice president Henry Wallace, argued that the tough line was provoking a conflict that could have been avoided. Historians still debate who started the Cold War, and the answer depends partly on which archives you read; Soviet documents opened after 1991 changed several arguments. What is clear is that by 1948 both sides believed the other would seize any opening.

Berlin lay a hundred miles inside the Soviet zone of occupied Germany, divided among the four Allied powers. In June 1948, angry that the western Allies were creating a separate West German state, Stalin cut every road and rail line into the western sectors of the city. Two million people faced starvation or surrender. Truman refused to give up the city and refused to shoot his way in. Instead, for eleven months, American and British planes landed in West Berlin around the clock, one every few minutes, carrying coal, flour and milk. The Berlin airlift delivered more than two million tons. In May 1949 Stalin lifted the blockade.

The crisis convinced Western Europe and the United States to bind themselves together. In April 1949 twelve countries signed the North Atlantic Treaty, creating NATO. Its core promise is that an attack on any member is an attack on all. For the first time in its history, the United States joined a permanent military alliance in peacetime and stationed troops in Europe to stay. The Soviet Union answered with its own alliance, the Warsaw Pact, in 1955. Germany itself was split into two countries, and in 1961 the East German government built a wall through Berlin to stop its people fleeing west.

Then two shocks in the fall of 1949. In August the Soviet Union tested its own atomic bomb, years before American experts had expected. In October Mao Zedong’s Communists won the civil war in China, the world’s most populous country. To many Americans it seemed that communism was winning everywhere and that spies must be to blame. Truman ordered a crash program to build the hydrogen bomb, a weapon hundreds of times more powerful than the one dropped on Hiroshima, and a secret planning document called for a huge increase in military spending to meet a global threat.

By the mid-1950s both sides had hydrogen bombs and were building missiles to deliver them across oceans. Each could destroy the other within an hour, and neither could stop an attack. Strategists called this mutual assured destruction: peace kept by the certainty that any war would kill everyone. Schoolchildren practiced duck-and-cover drills. Families in the Chicago suburbs dug backyard shelters. The arms race would consume trillions of dollars and shape science, schools and politics for a generation.

Korea had been divided at the end of World War II along the thirty-eighth parallel, with a Soviet-backed Communist state in the north and an American-backed state in the south. On June 25, 1950, North Korean troops with Soviet tanks poured across the line and nearly overran the whole peninsula. Truman decided within days that this was the test of containment. He sent American forces under the flag of the United Nations, which the Soviets had been boycotting and so could not veto. He never asked Congress for a declaration of war, calling it a police action, a precedent every president since has used.

In September General Douglas MacArthur landed troops far behind North Korean lines at Inchon, a brilliant gamble that collapsed the invasion. American and UN forces chased the North Koreans back across the parallel and drove toward the Chinese border, aiming now to unite Korea. In November, hundreds of thousands of Chinese soldiers crossed the border and sent the Americans into the longest retreat in their history through a brutal winter. When MacArthur publicly demanded permission to attack China itself, Truman fired him in April 1951 for defying civilian control of the military. Many Americans were furious, but the principle held.

For two more years the war settled into trench fighting near the thirty-eighth parallel while negotiators argued, mostly over prisoners who did not want to go home. An armistice signed in July 1953 stopped the shooting but never became a peace treaty; the two Koreas remain technically at war, separated by the most heavily armed border on earth, with American troops still stationed in the south. About thirty-six thousand Americans died. Korean deaths, civilian and military, on both sides, are estimated in the millions.

Korea set the pattern for the Cold War. It was a limited war: fought for limited goals, without nuclear weapons, in a place most Americans could not find on a map, and ended by negotiation rather than victory. It tripled the American defense budget and left the country with bases across Asia. It also showed how the Cold War could turn hot far from either superpower, with the people who lived there paying most of the price. Americans often call it the forgotten war, which tells you something about how nations remember wars that end in a draw.

There were real Soviet spies in the United States. Klaus Fuchs, a scientist at Los Alamos, gave the Soviets bomb secrets, and Julius Rosenberg ran a spy ring; he and his wife Ethel were executed in 1953. But the search for spies grew into something much larger. In 1947 Truman ordered loyalty checks for every federal employee. The House Un-American Activities Committee investigated Hollywood, and ten writers and directors who refused to answer went to prison. Studios kept a blacklist of people who would never work again. Teachers, union leaders and government workers lost jobs over meetings they had attended in the 1930s.

In February 1950 a little-known senator from Wisconsin, Joseph McCarthy, told an audience in West Virginia that he had a list of Communists working in the State Department. The number changed every time he spoke. He never produced the list. But the charge came days after the Soviet bomb and the fall of China, and it made him the most feared man in Washington. For four years he accused diplomats, professors, generals and journalists, usually with no evidence, and any senator who challenged him risked being called soft on communism. McCarthyism came to mean reckless accusation without proof.

The end came on television. In 1954 McCarthy took on the U.S. Army, and the hearings were broadcast live for weeks to about twenty million viewers. Americans watched him bully witnesses and interrupt everyone. When he attacked a young lawyer on the Army’s legal team, the Army’s counsel, Joseph Welch, asked him whether he had no sense of decency. The gallery applauded. In December the Senate formally condemned McCarthy’s conduct. He died three years later, largely ignored. The broader fear faded more slowly, and the blacklists lasted into the 1960s.

The episode raises questions the Constitution does not answer cleanly. The government has a duty to catch spies. It also has a duty not to punish people for their beliefs or their associations. Where is the line? Later evidence from Soviet archives confirmed some of the espionage, and also confirmed that the vast majority of McCarthy’s targets were innocent. Historians use the era to study how fear travels through a democracy and what stops it.

Between 1946 and 1964 Americans had about seventy-six million babies, a baby boom that reshaped every school, store and neighborhood. Returning veterans married young and wanted houses that did not exist. A builder named William Levitt applied the assembly line to housing: crews moved down a street doing one task each, and a house went up in a day. His first Levittown on Long Island had seventeen thousand nearly identical homes. GI Bill and federal loans meant a veteran could buy one for almost nothing down, often for less per month than city rent. By 1960 a quarter of Americans lived in suburbs.

The car made the suburb possible, and the government made the car king. In 1956 President Eisenhower, who remembered a miserable Army convoy across the country in 1919 and the German autobahns in 1945, signed the Interstate Highway Act. It funded about forty-one thousand miles of limited-access highway, the largest public works project in American history, justified partly as a way to evacuate cities in a nuclear attack. Chicago’s expressways date from these years. Highways carried families out of the city and shopping malls followed them. Towns bypassed by the interstate withered.

The suburbs were not open to everyone. Federal loan agencies refused to insure mortgages in neighborhoods they marked in red on their maps, mostly Black and mixed neighborhoods, a practice called redlining. Levitt’s contracts barred sales to Black buyers, and when a Black family moved into a Levittown in 1957, mobs gathered for weeks. In Chicago, highways were routed through Black neighborhoods, and public housing towers concentrated poor families on the South and West Sides. The suburbs built white middle-class wealth in homes that gained value; Black families were largely locked out of that wealth.

Life in the new suburbs had its critics. Writers worried about conformity, about identical houses full of identical families watching identical television. Women who had worked during the war found themselves expected to stay home, and a 1963 book by Betty Friedan gave a name to their restlessness. Television itself, in almost no homes in 1948 and nearly ninety percent by 1960, became the country’s shared culture. The teenagers of the boom, with money and cars, invented rock and roll audiences. The suburbs were prosperous and often happy, and they set up the conflicts of the next decade.

On October 4, 1957, the Soviet Union launched Sputnik, a polished metal sphere the size of a beach ball that circled the earth every ninety-six minutes, beeping. Americans could hear it on the radio and, at dawn, see the rocket that carried it. The shock was enormous. The rocket that could lift a satellite could carry a hydrogen bomb to any American city. The country that had assumed it led the world in science had been beaten by a nation it thought backward. A month later the Soviets launched a dog into orbit. An American attempt in December rose four feet and exploded on live television.

The response reached into every classroom. Congress created NASA in 1958 and passed the National Defense Education Act, which poured money into science, math and foreign language teaching and into college loans; if you have taken a federal student loan, it began here. The Soviets kept winning. In April 1961 Yuri Gagarin became the first human in orbit. Three weeks later Alan Shepard made a fifteen-minute flight that did not reach orbit. President Kennedy, looking for a contest the United States could win, asked Congress in May 1961 to commit to landing a man on the Moon and returning him safely before the decade was out.

It was a staggering promise. No one knew how to do it. Over eight years NASA spent about twenty-five billion dollars, employed some four hundred thousand people, and lost three astronauts in a launch-pad fire in 1967. The program built rockets taller than the Statue of Liberty and computers small enough to fly. Much of the engineering was done by contractors in Texas, California and Florida, and much of the calculation, in the early years, by women mathematicians whose names were left out of the story for decades.

On July 20, 1969, Neil Armstrong and Buzz Aldrin landed on the Moon while about six hundred million people watched on television, the largest audience in history to that point. Americans landed there six times in all. Critics then and since have asked whether the money could have been better spent on earth, and the Moon landings did not change the balance of the Cold War. But the race produced satellites for weather and communication, the computer industry, and a generation of scientists. It also produced a photograph of the earth from space, small and alone, that helped start the environmental movement.

The story that opened this chapter did not come from nowhere. In 1959 Fidel Castro had overthrown a dictator in Cuba and, when the United States turned hostile, allied with the Soviet Union. In April 1961 Kennedy allowed an invasion by Cuban exiles trained by the CIA at the Bay of Pigs. It failed in three days, humiliating the new president. Khrushchev concluded that Kennedy was weak, and in 1962 he sent missiles to Cuba, partly to defend Castro and partly to offset the American lead in missiles and American weapons in Turkey. The photographs of October 14 found them.

The thirteen days changed both men. Kennedy had seen how close a chain of small decisions could come to catastrophe, and Khrushchev had seen the same. Within a year they installed a direct teletype link, the hot line, so leaders could talk in a crisis instead of guessing. In August 1963 they signed the Limited Test Ban Treaty, ending nuclear tests in the atmosphere, which had been spreading radioactive fallout across the globe, into milk and children’s teeth. It was the first agreement of the nuclear age to restrain the weapons themselves.

Kennedy gave a speech in June 1963 asking Americans to re-examine their view of the Soviet Union and to remember that both peoples breathed the same air and cherished their children’s future. Five months later he was assassinated in Dallas, on November 22, 1963. Khrushchev was removed by his own colleagues the next year, partly for the humiliation of Cuba. The arms race did not stop; both sides built thousands more missiles, and by the 1980s the world held tens of thousands of nuclear warheads. But the pattern of talking, testing limits and signing treaties began in the aftermath of October 1962.

Historians use the crisis to study how decisions get made under pressure. Tapes Kennedy secretly recorded in the Cabinet Room let us hear the advisers argue in real time. They show that the president’s early instinct was an air strike, that he changed his mind, that his brother and the defense secretary pushed for the blockade, and that Kennedy was more willing to compromise than his public words suggested. They are a reminder that the confident story told afterward is rarely the whole story.

Lyndon Johnson took the oath on the plane that carried Kennedy’s body home from Dallas. He had spent his life in Congress and knew how to make it move. In 1964 he pushed through the Civil Rights Act that Kennedy had proposed, then won the presidency in November by the largest share of the popular vote in history. He called his program the Great Society: a country that would end poverty and racial injustice and give every child a decent education. In 1965 Congress passed more major laws than in any year since the New Deal.

The largest was Medicare, health insurance for everyone over sixty-five, paid for through Social Security taxes, along with Medicaid, health coverage for the poor paid by the federal and state governments together. Before 1965 about half of older Americans had no health insurance and a serious illness could wipe out a family. The Elementary and Secondary Education Act sent federal money to schools for the first time, targeted at poor districts. Head Start opened preschools for poor children. The Voting Rights Act, which you will study in the next unit, protected the right to vote. New laws opened immigration to Asia, Africa and Latin America for the first time since 1924.

Johnson also declared a war on poverty: job training, community action programs run partly by poor people themselves, food stamps and legal aid. The poverty rate fell from about nineteen percent in 1964 to about twelve percent in 1969, and the drop among older Americans was even steeper. Critics on the right argued that the programs were wasteful, that they created dependence and that a booming economy, not government, was lifting people. Critics on the left argued that the war on poverty was never funded seriously and was starved by another war, in Vietnam.

The Great Society also created public television, national endowments for the arts and humanities, the first major laws to clean air and water, and consumer safety rules for cars. Much of it survives; Medicare and Medicaid now cover more than a third of Americans. The argument over it is the same one that began in the 1930s. Illinois today runs Medicaid, spends federal school aid and relies on Head Start, so the debate is not abstract. Every state budget is partly a vote on the Great Society.

Vietnam had fought France for independence and won in 1954. The country was then divided, with a Communist government under Ho Chi Minh in the north and an American-backed government in the south. American leaders believed in the domino theory: if Vietnam fell to communism, its neighbors would fall one by one. Eisenhower sent aid; Kennedy sent about sixteen thousand military advisers. By 1964 the southern government was losing to Communist guerrillas, the Viet Cong, supplied from the north. In August 1964, after reports of attacks on American ships in the Gulf of Tonkin, Congress gave Johnson broad power to use force. The second attack, it later turned out, probably never happened.

In 1965 Johnson began bombing North Vietnam and sending combat troops. By 1968 there were more than five hundred thousand Americans in Vietnam, most of them drafted, average age nineteen. They fought an enemy that hid among villagers, in tunnels and in jungle, and that could retreat across borders the Americans were not allowed to cross. Success was measured in enemy dead, a number that was often inflated. American bombing dropped more explosives on Vietnam than all sides had used in World War II, and chemicals sprayed to strip the jungle poisoned land and people for decades. Vietnamese deaths, north and south, soldier and civilian, are estimated in the millions.

In January 1968, during the Tet holiday, Communist forces attacked more than a hundred cities across the south at once, even breaching the American embassy in Saigon. Militarily the Tet Offensive failed; the attackers lost tens of thousands. But Americans had been told for years that victory was near, and the pictures on television said otherwise. Support for the war collapsed. In March, Johnson announced he would not run for re-election. That same month, in a village called My Lai, American soldiers murdered hundreds of unarmed civilians, a crime covered up for more than a year.

Richard Nixon, elected in 1968, promised to end the war and instead widened it into Cambodia while slowly withdrawing American troops. In 1971 a leaked secret history, the Pentagon Papers, showed that leaders had doubted the war could be won even as they sent more troops. A peace agreement in January 1973 brought the last American troops home. In April 1975 North Vietnam took Saigon. About fifty-eight thousand Americans had died, their names now carved on a black granite wall in Washington. The war left a deep distrust of government claims that shapes American politics still.

Opposition to the war began on college campuses with teach-ins in 1965 and grew with the draft. Young men burned draft cards, fled to Canada or went to prison; the boxer Muhammad Ali refused induction and was stripped of his title. In 1967 about a hundred thousand people marched on the Pentagon. Martin Luther King Jr. came out against the war that year, saying it was draining money from the poor and sending Black men to die for freedoms they did not have at home. By 1969 hundreds of thousands were marching in Washington, and polls showed most Americans thought the war had been a mistake.

The antiwar movement argued that the war was unwinnable, that it was killing civilians, and that the government was lying about it. Supporters of the war, still a large group, argued that retreat would abandon an ally and embolden the Soviets and China, and that protesters were undermining soldiers in the field. Families split over dinner tables. Veterans came home to a country that often did not want to hear about what they had seen. In May 1970, after Nixon expanded the war into Cambodia, National Guard troops fired on protesters at Kent State University in Ohio and killed four students. Campuses across the country shut down.

Alongside the protests grew something looser: the counterculture. Young people grew their hair, wore what they liked, experimented with drugs, and questioned rules about sex, work and authority. Rock music was its language, from folk singers at protests to the three-day Woodstock festival in 1969. Communes and underground newspapers sprang up. Some of it was serious rethinking of how to live; some of it was fashion. Older Americans, including many who opposed the war, were baffled or angry. Nixon appealed to what he called the silent majority who did not protest and wanted order.

The movements of the era, for civil rights, against the war, for women, for the environment, borrowed from each other and argued with each other. They shared a suspicion of authority that the Pentagon Papers and later Watergate seemed to confirm. Their lasting effects include the end of the draft in 1973, the vote for eighteen-year-olds in 1971, and a permanent change in how Americans dress, talk and question leaders. Their limits are also clear: the war went on for years after most people opposed it, which raises hard questions about how much protest can do.

By August 1968 the year had already broken the country’s nerve. Martin Luther King Jr. was murdered in Memphis on April 4, and riots burned Chicago’s West Side for days; Mayor Richard J. Daley ordered police to shoot to kill arsonists. Robert Kennedy, running for president against the war, was shot dead in Los Angeles in June. Johnson had quit the race. The Democrats came to Chicago’s International Amphitheatre to choose between Vice President Hubert Humphrey, who had the delegates and Johnson’s war policy, and antiwar senators who had the voters in the primaries.

Thousands of protesters came too, a mix of serious antiwar organizers and theatrical radicals who nominated a pig for president. Daley refused nearly every permit and ringed the hall with barbed wire. He had about twelve thousand police, plus National Guard and Army troops, ready. On the night of Wednesday, August 28, as the convention voted down an antiwar platform, police charged protesters in front of the Conrad Hilton hotel on Michigan Avenue. Television cameras filmed officers clubbing demonstrators, reporters and bystanders. The crowd chanted that the whole world was watching. Inside the hall, a senator from Connecticut denounced Gestapo tactics from the podium while Daley shouted back from the floor.

A government commission studied the week and, in a report written by a Chicago lawyer named Daniel Walker, called what happened a police riot: unrestrained violence by police against people who had mostly done nothing to provoke it, while also noting that some protesters had thrown things and taunted officers. Daley’s defenders said the police had protected the city from people who came to cause trouble, and polls showed most Americans sided with the police. Eight protest leaders were tried in Chicago on conspiracy charges in a trial that became its own spectacle.

Humphrey was nominated in a hall that smelled of tear gas and lost narrowly in November to Richard Nixon, who promised law and order. Historians see 1968 as the year the New Deal coalition of the 1930s came apart: white working-class voters angry at protesters and riots moved right, while young activists lost faith in the party. Chicago changed its rules afterward, and so did the Democrats, opening the choice of nominees to primary voters. The convention’s lessons about protest, policing and cameras are studied every time a city hosts one.