Of Irish descent, he was born in Brookline, Mass., on May 29, 1917. Graduating from Harvard in 1940, he entered the Navy. In 1943, when his PT boat was rammed and sunk by a Japanese destroyer, Kennedy, despite grave injuries, led the survivors through perilous waters to safety. Back from the war, he became a Democratic congressman from the Boston area, advancing in 1953 to the Senate. He married Jacqueline Bouvier on Sept. 12, 1953. In 1955, while recuperating from a back operation, he wrote "Profiles in Courage," which won the Pulitzer Prize in history.