After graduating high school in 1942, he joined the Army as a rifleman. He had wanted to be a Navy flier, but his 6 foot 6inch height barred him from being a pilot. He took part in the landings at Anzio and was severely wounded, resulting in operations, honorable discharge, and leg trouble that would bother him the rest of his life. He had trouble walking for long periods and mounting a horse was difficult. During his service he was awarded the Bronze Star, the Purple Heart, the World War II Victory Medal and three Bronze Campaign Stars.
He played supporting roles in many films (including the John Wayne films, "Island in the Sky" and "Big Jim McLain", and "The Farmer's Daughter") before playing the lead role as Marshall Matt Dillon on the long-running TV show, "Gunsmoke". He was made an honorary US Marshal for "in recognition of his unique contribution to the image and traditions of the U.S. Marshal's Service".