Harry S. Truman assumed the U.S. presidency in 1945, just months after he had been inaugurated as the nation's 34th vice president. Truman had been a surprise choice for running mate when the popular Franklin D. Roosevelt sought a fourth presidential term. As vice president for 82 days, Truman spent most of his time presiding over the Senate. With Roosevelt's sudden death on April 12, 1945, Truman became the 33rd U.S. president and immediately faced the challenge of ending World War II.
Truman was born in Lamar, Missouri, and spent much of his childhood on his grandmother's 600-acre farm near Grandview, Missouri. At the age of 30, he began operating the farm himself, and for the rest of his life he identified himself as a farmer. At 33, Truman enlisted in the U.S. Army at the outbreak of World War I; he commanded an artillery battery in the Meuse-Argonne offensive and eventually attained the rank of major.
When he returned to Missouri after the war, Truman operated a haberdasher's shop and soon was elected judge of Jackson County. By then he was active in the Democratic Party, and in 1934 he was elected to the U.S. Senate, where he served for a decade and spent some of his happiest years. Truman supported the New Deal and provided strong chairmanship of the Senate Special Committee to Investigate the National Defense Program, popularly know as the Truman Committee, which promoted efficiency and economy during World War II.
In 1944 Truman's life took a surprising turn when the Democratic Party leaders decided to drop Vice President Henry A. Wallace from the ticket, and Truman became the reluctant replacement nominee at the Democratic convention. The Roosevelt-Truman ticket won easily, but already Roosevelt's health was failing. He died of a cerebral hemorrhage less than three months after his inauguration.
In May 1945, a month into Truman's presidency, Germany surrendered to Allied forces. However, the war in the Pacific against Japan continued. Truman, in a still-controversial action, authorized the dropping of the atomic bomb on the Japanese cities of Hiroshima and Nagasaki in August. As a result, the Japanese surrendered formally on September 2, 1945, ending World War II.
The Truman administration advanced the New Deal's domestic programs while helping to rebuild war-torn Europe. In 1948 Truman desegregated the armed forces, a controversial action that affected his popularity in that year's presidential race. In a well-known upset over Republican Thomas E. Dewey, however, Truman was reelected. Concerned with the spread of Communism abroad, he advocated a policy of containment–known as the Truman Doctrine–to restore the balance of power in Europe. In 1950 Truman sent American armed forces to defend South Korea. The following year, he dismissed General Douglas MacArthur from command in Korea for insubordination. The much-admired MacArthur had publicly advocated an attack on Communist China, directly challenging the position of his commander-in-chief, the president.
Truman decided against a reelection bid in 1952. Instead, he retired to his home in Independence, Missouri, where he remained active until his death in 1972.