After working several years as a director of amateur theatrical groups and an entertainment director at summer resorts, he scored his first Broadway hit with "Once in a Lifetime" (1930), a farce about the arrival of the sound era in Hollywood. The play was written in collaboration with Broadway veteran George S. Kaufman, who regularly wrote with others, notably Marc Connelly and Edna Ferber. (Kaufman also performed in the play's original Broadway cast in the role of a frustrated playwright hired by Hollywood.) During the next decade, Kaufman and Hart teamed on a string of successes, including "You Can't Take It with You" (1936) and "The Man Who Came to Dinner" (1939). Though Kaufman had hits with others, Hart is generally conceded to be his most important collaborator.