Harry S. Truman was the 33rd President of the United States, serving from 1945 to 1953. He took office after the death of Franklin D. Roosevelt and is best known for making the decision to use atomic bombs on Hiroshima and Nagasaki, which helped end World War II. Truman's presidency also saw the beginning of the Cold War, the establishment of the Marshall Plan to aid European recovery, and the creation of the North Atlantic Treaty Organization (NATO). His leadership style was characterized by decisiveness and a commitment to civil rights, making significant strides in desegregating the military.