Bush began acting on stage and was an original member of New York's Negro Ensemble Company starting in 1967, alongside Hattie Winston, Rosalind Cash, Clarice Taylor, Frances Foster, and later Graham Brown. He appeared in many of the company's off-Broadway productions through the seventies. Film work included The Pawnbroker, Across 110th Street, Three Days of the Condor (with Robert Redford), The Super Cops, and the TV movie The Connection (with Charles Durning). He appeared in an episode of the 1976 PBS series The Adams Chronicles as Cinque (leader of the Amistad mutiny).