His father Joseph Kennedy had the most influence on John F. Kennedy, followed by his brothers, particularly Joe, his older brother and rival. Joseph Kennedy had high ambitions for his sons, especially Joe, whom the father hoped would one day be president.
When Joseph Kennedy became U.S. Ambassador to England before World War II, John became interested in government and world affairs. Then, during World War II, while John served in the U.S. Navy, his brother Joe was killed when his plane exploded in Europe. With Joe gone, Joseph Kennedy turned to John and convinced him to pursue a career in politics. John Kennedy won a seat in Congress in 1946, served three terms and was then elected to the U.S. Senate. He was elected the 35th U.S. president in 1960. His younger brother Robert was influential as his confidant and advisor and as U.S. Attorney General during John F. Kennedy's presidency.