William O. Douglas
William Orville Douglas (October 16, 1898January 19, 1980) was an American jurist and politician who served as an associate justice of the Supreme Court of the United States from 1939 until 1975. He was known for his strong progressive views. He is seen as the Supreme Court's most liberal justice ever, and supported expanding individual rights on a number of fields. So far, he served the longest time of any justice, and wrote the most opinions.