A collector of antiques, his favorite sport was deep sea fishing.
After Starsky and Hutch (1975) ended, Hamilton spent twenty years producing R&B and Gospel records for the Chocolate Snowman label.
He attended Oakland Technical High School where he played football and studied acting in Oakland, California.
Operated the Citadel d'Haiti, a nightclub-art gallery on Sunset Boulevard in Los Angeles during the late '60s and early '70s.
Managed to avoid stereotyping for the most part in his early films years, his debut was as a baseball player in The Jackie Robinson Story (1950). His most important role was in the frank, groundbreaking drama One Potato, Two Potato (1964) as the black husband of a white woman (Barbara Barrie).