John Fitzgerald Kennedy (May 29, 1917 – November 22, 1963), often referred to by his initials JFK or by his nickname Jack, was an American politician who served as the 35th president of the United States from January 1961 until his assassination in November 1963. Kennedy served at the height of the Cold War, and the majority of his work as president concerned relations with the Soviet Union and Cuba. He was subsequently elected to the U.S. Senate and served as the junior Senator from Massachusetts from 1953 to 1960.