Edward Kennedy, the youngest child of Rose and Joseph Kennedy (Kennedy, Joseph P.) and the last surviving brother of Pres. John F. Kennedy (Kennedy, John F.), graduated from Harvard University in 1956. He then studied at the International Law School (The Hague) and received a law degree from the University of Virginia (1959). Edward campaigned for his brother John in the 1960 presidential race, and in 1962 he was elected to the president's former U.S. Senate seat representing Massachusetts. Although unable to campaign actively for reelection (1964) for a full term because of an injury, he was swept back into office by a landslide vote.

Early in 1969 he was elected majority whip in the U.S. Senate, and he became an early front-runner for the next Democratic presidential nomination. Then, on the night of July 18, 1969, he accidentally drove his car off an unmarked bridge on Chappaquiddick Island, near Martha's Vineyard, Mass., and his companion in the car, 28-year-old Mary Jo Kopechne, was drowned. Kennedy was found guilty of leaving the scene of an accident. He was reelected to the Senate in 1970 but announced that he would not seek the presidency in 1972.

Kennedy won reelection to a third full term as senator in 1976. He was a serious contender for the 1980 Democratic presidential nomination but withdrew from the race during the convention. He won a fourth term in 1982 and was again reelected to the Senate in 1988, 1994, 2000, and 2006.

Kennedy continued to be a prominent spokesman for the policies that had come to be associated with his family name—i.e., support for social welfare legislation and active participation in world affairs. He became a leading advocate in the Senate for many liberal causes, including voting rights (Voting Rights Act), fair housing, consumer protection (consumer advocacy), and national health insurance. At the same time, he was recognized for his willingness to cooperate with Republicans in the Senate to advance important legislation, such as the No Child Left Behind Act (No Child Left Behind) (2001) and other initiatives of the administration of Pres. George W. Bush (Bush, George W.). In 2008, after being hospitalized for a seizure, Kennedy was diagnosed with a malignant brain tumour.