John Fitzgerald Kennedy (May 29, 1917 – November 22, 1963), often referred to by his initials JFK and by the nickname Jack, was an American politician who served as the 35th president of the United States from 1961 until his assassination in 1963. He was the youngest person to assume the presidency by election and the youngest president at the end of his tenure. Kennedy served at the height of the Cold War, and the majority of his foreign policy concerned relations with the Soviet Union and Cuba. A Democrat from Massachusetts, Kennedy served in both houses of the U.S. Congress prior to his presidency.