Slade began his career as a theatrical producer and stage actor in Canada. His success there led to a contract with Screen Gems, where he was assigned to write three television pilots per year. His work there resulted in the show Love On A Rooftop, which lasted one season, and The Flying Nun, which ran for three seasons and boosted the career of Sally Field.
His greatest success was 1970’s The Partridge Family, the tale of a musical family that traveled by bus. Shirley Jones was the mother of a singing family, which included stepson David Cassidy, whose good looks and smooth voice spawned nationwide teenage devotion.