Came from a family of entertainers: His father was noted film director John Cromwell (Since You Went Away, Abe Lincoln in Illinois) and his mother, Kay Johnson, was an actor.
First major TV role came in 1974, when he won the part of Archie Bunker's pal Jerome "Stretch" Cunningham on the sitcom All in the Family.
Made his big-screen debut in the 1976 mystery spoof Murder by Death.