In September 1939 Roosevelt called Congress into special session to revise the neutrality acts. The president offered a plan known as cash-and-carry, which permitted Americans to sell munitions to nations able to pay for them in cash and able to carry them away in their own ships. Congress passed the Neutrality Act of 1939, which legitimized cash-and-carry and allowed Britain and France to buy American arms. The war in Europe, meanwhile, grew more dire for the Allies. In June 1940 Germany conquered France, and British troops that had been in France retreated across the English Channel. Then German bombers began to pound Britain.
In June 1940 the United States started supplying Britain with “all aid short of war” to help the British defend themselves against Germany. Roosevelt asked Congress for more funds for national defense. Congress complied and began the first American peacetime military draft, the Selective Training and Service Act, under which more than 16 million men were registered. After the 1940 election, Roosevelt urged that the United States become “the great arsenal of democracy.” However, the United States was still not actually at war.
In 1941 the conflict worsened. Despite the nonaggression pact, German armies invaded the USSR. Meanwhile, as Japan continued to invade areas in Asia, U.S. relations with Japan crumbled. On December 7, 1941, Japan attacked a U.S. naval base at Pearl Harbor in Hawaii. The next day it attacked the main American base in the Philippines. In response, the United States declared war on Japan, although not on Germany; Hitler acted first and declared war on the United States. The United States committed itself to fighting the Axis powers as an ally of Britain and France.
Even before Pearl Harbor, the American government had begun to mobilize for war. After the attack, the United States focused its attention on the war effort. World War II greatly increased the power of the federal government, which mushroomed in size and power. The federal budget skyrocketed, and the number of federal civilian employees tripled. The war also made the United States a military and economic world power.
The armed forces expanded as volunteers and draftees enrolled, growing to almost 12 million men and 260,000 women by 1945. Roosevelt formed the Joint Chiefs of Staff, a military advisory group, to manage the huge military effort. New federal agencies multiplied. The Office of Strategic Services gathered intelligence and conducted espionage, the War Production Board distributed manufacturing contracts and curtailed manufacture of civilian goods, and the War Manpower Commission supervised war industry, agriculture, and the military. Other wartime agencies resolved disputes between workers and management; battled inflation, set price controls, and imposed rations on scarce items; turned out propaganda; and oversaw broadcasting and publishing.
Labor scarcity drew women into the war economy. During the depression, the federal government had urged women to cede jobs to male breadwinners. However, when the war began, it sought women to work in war production. More than 6 million women entered the work force in wartime; women’s share of the labor force leaped from 25 percent in 1940 to 35 percent in 1945. Three-quarters of the new women workers were married, a majority were over 35, and over a third had children under 14. Many women held untraditional jobs in the well-paid blue collar sector—in shipyards and in airplane plants, as crane operators. Women found new options in civilian vocations and professions, too. Despite women’s gains in the workplace, many people retained traditional convictions that women should not work outside the home. Government propaganda promoted women’s war work as only a temporary response to an emergency.
For all Americans, war changed the quality of life. World War II inspired hard work, cooperation, and patriotism. Citizens bought war bonds, saved scrap metal, and planted victory gardens. They coped with rationing and housing shortages. The war also caused population movement. Americans flocked to states with military bases and defense plants; 6 million migrants left for cities, many on the West Coast, where the defense industry was concentrated. School enrollment sank as teenagers took jobs or joined the armed services. People became more concerned about family life, especially about working mothers, juvenile delinquency, and unruly teenagers.
In the United States, civil liberties were casualties of the war. In February 1942 the president authorized the evacuation of all Japanese from the West Coast. The U.S. government interned around 120,000 Japanese Americans, two-thirds of them native-born U.S. citizens, in relocation centers run by the War Relocation Authority. The internment policy reflected anti-Japanese sentiment on the West Coast that was rooted in economic rivalry, racial prejudice, and fear of Japanese sabotage after Pearl Harbor. In 1944 the Supreme Court ruled that the evacuation and internment were constitutional. By then, however, the government had started to release the internees. In 1988 Congress apologized and voted to pay $20,000 compensation to each of 60,000 surviving internees.
Ever since 1941, when Roosevelt and Churchill issued the Atlantic Charter outlining war goals, the president had considered the war’s conclusion. At wartime conferences, Allied leaders looked ahead to the war’s end. However, the Western powers and the USSR did not trust one another and disagreed on the postwar future of nations on the Soviet border.
In 1944 the war in the European theater reached a climax. The USSR then moved into Poland and the Balkans, and pushed the Allies to open a second front in Western Europe. The Allied armies prepared a huge invasion of western France. On June 6, 1944, known as D-Day, thousands of vessels and aircraft carrying British, Canadian, American troops crossed the English Channel and landed on the Normandy coast of France. On August 25, 1944, the Allied forces liberated Paris after four years of Nazi rule. The Germans continued to fight in eastern France. Hitler launched a last, desperate offensive, the Battle of the Bulge, in December 1944. The offensive failed, and German armies were forced to retreat. Allied armies entered Germany in March 1945, while the Soviets moved toward Berlin from the east. Germany surrendered on May 8, 1945. The war in Europe was over.
The Pacific war continued. After the attack on Pearl Harbor, Japan conquered the Philippines, Malaya, the Dutch East Indies, and Burma. Troops from the United States, Britain, Australia, and New Zealand tried to stop the Japanese advance, which reached its peak in the spring of 1942. The turning point of the Pacific war came in June 1942, at the Battle of Midway. The American victory at Midway ended the Japanese navy’s hope of controlling the Pacific. The United States then began a long counteroffensive and recaptured Pacific islands that the Japanese had occupied. In October 1944 the United States finally smashed the Japanese fleet in the Battle of Leyte Gulf in the Philippines.
But Japan refused to surrender. The United States wanted to end the war with unconditional surrender from Japan. It also wanted to avoid more battles like those in Iwo Jima and Okinawa, where U.S. casualties had been heavy. These factors spurred U.S. plans to use the atomic bomb.
The United States in late 1941 established a secret program, which came to be known as the Manhattan Project, to develop an atomic bomb, a powerful explosive nuclear weapon. After Roosevelt’s death in April 1945, Harry S. Truman became president and inherited the bomb-development program. At this point, the new weapon had two purposes. First, it could be used to force Japan to surrender. Second, possession of the bomb would enable the United States, and not the USSR, to control postwar policy.
On August 6, 1945, the United States dropped an atomic bomb on Hiroshima. In minutes, half of the city vanished. According to U.S. estimates, 60,000 to 70,000 people were killed or missing as a result of the bomb. Deadly radiation reached over 100,000. On August 8, the USSR declared war on Japan. On August 9, the United States dropped an even more powerful bomb on Nagasaki. According to U.S. estimates, 40,000 people were killed or never found as a result of the second bomb. On September 2, the Japanese government, which had seemed ready to fight to the death, surrendered unconditionally.
World War II ended Nazi barbarism and vanquished totalitarian power that threatened to conquer the globe. The cost of the war was immense. Allied military and civilian losses were 44 million; those of the Axis, 11 million. The United States lost almost 300,000 people in battle deaths, which was far less than the toll in Europe and Asia. At home, the war quenched isolationism, ended the depression, provided unprecedented social and economic mobility, fostered national unity, and vastly expanded the federal government. The U.S. government spent more than $300 billion on the war effort, which generated jobs and prosperity and renewed confidence. Finally, World War II made the United States the world’s leading military and economic force. With the Axis threat obliterated, the United States and the USSR became rivals for global dominance.