Despite his undeniable talent and magnetism, Clark never took off as a star the way his friend John Garfield did, even after his scene-stealing turn in "Hollywood Canteen" (1944), a performance alongside such notables as Bette Davis, Joan Crawford and Jack Benny. His prolific acting career included starring turns in dozens of films in the 40s and 50s, including a memorable portrayal of Abe Saperstein in "Go, Man, Go!" (1954), the story of the creation of basketball's famous Harlem Globetrotters. Clark eventually left Hollywood to work on the stage and in features produced overseas. He worked for J Arthur Rank in London, appearing in 1950's "Highly Dangerous" and 1952's "The Gambler and the Lady". In 1968, he starred in the Denmark/US co-production "Dage i Min Fars Hus/Days in My Father's House".
Clark returned to the stage after achieving film success, starring in many Broadway productions (e.g., "A Thousand Clowns" in which he replaced Jason Robards). He was also a frequent presence on the small screen, first appearing in several of the theater anthology programs that were popular in the medium's early days. Clark made his series debut as legal aid lawyer Richard Adams in the NBC drama "Justice" (1954-56) and headlined the 1959 syndicated series "Bold Venture". Throughout much of the 60s, 70s and 80s, Clark was a familiar face as a guest performer on shows as varied as "The Twilight Zone", "I Spy", "The Mod Squad" and "Murder, She Wrote". He returned to series work as a police lieutenant in the CBS remake "The New Adventures of Perry Mason" (1973-74). Clark made his last film appearance in 1988's "Last Rites" starring Tom Berenger. The veteran actor died in 1998, battling cancer.