William Orville Douglas (October 16, 1898 – January 19, 1980) was an American jurist who served as an associate justice of the Supreme Court of the United States, who was known for his strong progressive and civil libertarian views, and is often cited as the U.S. Supreme Court's most liberal justice ever. In 1975, Time called Douglas "the most doctrinaire and committed civil libertarian ever to sit on the court." He is the longest-serving associate justice in history, with his term lasting 36 years and 211 days (1939–1975).