Claim: John F. Kennedy was a member of the Democratic Party.

John Fitzgerald `` Jack '' Kennedy -LRB- May 29 , 1917 -- November 22 , 1963 -RRB- , commonly referred to by his initials JFK , 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 much of his presidency focused on managing relations with the Soviet Union . He was a member of the Democratic Party who represented Massachusetts in the United States House of Representatives and the United States Senate prior to becoming president .   Kennedy was born in Brookline , Massachusetts to Joseph P. Kennedy , Sr. and Rose Kennedy . A scion of the Kennedy family , he graduated from Harvard University in 1940 before joining the United States Naval Reserve the following year . During World War II , Kennedy commanded a series of PT boats in the Pacific theater and earned the Navy and Marine Corps Medal for his service . After the war , Kennedy represented Massachusetts 's 11th congressional district in the United States House of Representatives from 1947 until 1953 . He was subsequently elected to the U.S. Senate and served as the junior Senator from Massachusetts from 1953 until 1960 . While serving in the Senate , he published Profiles in Courage , which won the Pulitzer Prize for Biography . In the 1960 presidential election , Kennedy narrowly defeated Republican opponent Richard Nixon , who was the incumbent Vice President .   Kennedy 's time in office was marked by high tensions with Communist states in the Cold War . He increased the number of American military advisers in South Vietnam by a factor of 18 over President Dwight D. Eisenhower . In April 1961 , he authorized a failed joint-CIA attempt to overthrow the Cuban government of Fidel Castro in the Bay of Pigs Invasion . He subsequently rejected plans by the Joint Chiefs of Staff to orchestrate false-flag attacks on American soil in order to gain public approval for a war against Cuba . In October 1962 , U.S. spy planes discovered that Soviet missile bases had been deployed in Cuba ; the resulting period of tensions , termed the Cuban Missile Crisis , nearly resulted in the breakout of a global thermonuclear conflict . Domestically , Kennedy presided over the establishment of the Peace Corps and supported the Civil Rights Movement , but he was largely unsuccessful in passing his New Frontier domestic policies . Kennedy continues to rank highly in historians ' polls of U.S. presidents and with the general public . His average approval rating of 70 % is the highest of any president in Gallup 's history of systematically measuring job approval .   On November 22 , 1963 , Kennedy was assassinated in Dallas , Texas . Lee Harvey Oswald was arrested for the crime , but he was never prosecuted due to his murder by Jack Ruby two days later . Pursuant to the Presidential Succession Act , Vice President Lyndon B. Johnson was sworn in as president later that day . The FBI and the Warren Commission officially concluded that Oswald was the lone assassin , but various groups believed that Kennedy was the victim of a conspiracy . After Kennedy 's death , many of his proposals were enacted , including the Civil Rights Act of 1964 and the Revenue Act of 1964 .