The youngest child of Carroll Livingston Wainwright, a painter, and the former Edith Kingdon Gould, a granddaughter of Jay Gould, Carroll Livingston Wainwright Jr. was born on the streets of New York City, in a Pierce-Arrow, on Dec. 28, 1925. He would divide his time between the Malcolm Gordon School, a boarding school in Garrison, N.Y., and the home of an uncle, Loudon Wainwright (grandfather of the singer and songwriter Loudon Wainwright III), in Hewlett, on Long Island. The arrangement continued after the death of Carroll’s mother in 1937, at 36, from alcohol-related liver disease. Lying about his age to enlist at 17, a young Mr. Wainwright served stateside as a Marine Corps pilot during World War II. He earned a bachelor’s degree in American studies from Yale in 1949 and a law degree from Harvard in 1952. From 1959 to 1960, Mr. Wainwright served as assistant general counsel to Gov. Nelson A. Rockefeller of New York. At Milbank, Tweed, he specialized in trusts and estates for clients including the Rockefeller family. He was the lead lawyer overseeing the sale of a controlling interest in Rockefeller Center to the Mitsubishi Estate Company in 1989. Mr. Wainwright was a member of the New York State Commission on Judicial Conduct from its inception in 1974 until 1983. From 1990 to 1997, he was an adjunct professor of law at Washington and Lee University in Lexington, Va. The many boards on which he sat included that of the Greater Yellowstone Coalition, devoted to conserving the Greater Yellowstone Ecosystem of Idaho, Montana and Wyoming. His work there included helping reintroduce wolves into the region in the 1990s. Mr. Wainwright’s death, at his home in East Hampton, on Long Island, was announced by his family. His survivors include his wife, the former Nina Walker, whom he married in 1948; two sons, D. Walker Wainwright and Mark L. Wainwright; four grandchildren; and three great-grandchildren. Mr. Wainwright’s sister, Caroline Wainwright Shean, died in 1969. His brother, Stuyvesant Wainwright II, a Republican who represented eastern Long Island in Congress from 1953 to 1961, died in 2010.