After serving in the U.S. Army from 1951 to 1954, Gravel attended Columbia University in New York City and received a bachelor's degree in 1956. He held a variety of jobs—including railroad brakeman and cab driver—before serving in the Alaska House of Representatives from 1963 to 1966. After losing a bid for election to the U.S. House of Representatives in 1966, Gravel was elected to the U.S. Senate in 1968 and became one of the most outspoken senatorial critics of the Vietnam War. In 1971 he made headlines when he undertook a five-month-long one-man filibuster that succeeded in killing legislation to extend the draft. That same year he introduced the Pentagon Papers into the public record by reading portions of them aloud in a subcommittee meeting. Gravel lost his reelection bid in 1980 and spent much of the following 25 years promoting increased citizen participation in government.