Kirk Douglas bought the film rights to the play as a gift to his son after Michael Douglas was fired from the stage production.
Despite his name being in the credits, William Smith does not appear in the movie.
Anthony Newley, the director of this film, was Oscar-nominated in 1971 but not for this film. His Oscar nod was for co-writing the score, with Leslie Bricusse and Walter Scarf, for "Willy Wonka and the Chocolate Factory."
Richard Stahl also appeared in another counter-culture movie, "Billy Jack" ( as the head of the city council) in the same year, 1971, that he appeared in "Summertree. "