Harry Truman (1884-1972), the 33rd U.S. president, assumed office following the death of President Franklin Roosevelt (1882-1945). In the White House from 1945 to 1953, Truman made the decision to use the atomic bomb against Japan, helped rebuild postwar Europe, worked to contain communism and led the United States into the Korean War (1950-1953). A Missouri native, Truman assisted in running his family farm after high school and served in World War I (1914-1918). He began his political career in 1922 as a county judge in Missouri and was elected to the U.S. Senate in 1934. Three months after becoming vice president in 1945, the plain-spoken Truman ascended to the presidency. In 1948, he was reelected in an upset over Republican Thomas Dewey (1902-1971). After leaving office, Truman spent his remaining two decades in Independence, Missouri, where he established his presidential library.