Born in San Francisco, California, Chamberlain graduated from Germantown Friends School in Philadelphia in 1937. He studied physics at Dartmouth College, where he was a member of Theta Chi Fraternity, and at the University of California, Berkeley. He remained in school until the start of World War II, and joined the Manhattan Project in 1942, where he worked with Segrè, both at Berkeley and in Los Alamos, New Mexico. He married Beatrice Babette Copper (d. 1988) in 1943, with whom he had four children.