Harry S. Truman (1884-1972) was the 33rd President of the United States. He was Vice-President under Franklin Delano Roosevelt until his death. The S in his name is just a letter. It was meant to stand for "Shippe" or "Solomon", which were the names of his grandfathers. He was the only 20th century President without a college degree. He was President when the atomic bomb was dropped on Japan. He led the US troops into the Korean War.