Big Jim McLain!
John Wayne's co-star was Jim Arness, who a short time later, went on to play Marshall Matt Dillon in Gunsmoke. John Wayne was offered the part of Marshall Dillion first, but turned it down. He suggested a firend of his might be perfect for the part. And Wayne introduced the very fiirst episode of Gunsmoke to America.
On TV only.
Gunsmoke was the creation of William Conrad who also played the character on radio for years before the TV show came out. "Chester" was played by Parley Bayer (sp?), "Kitty" was played by Georgia Ellis, and Howard McNeer (sp?) played "Doc."
The radio show also had great background music which was so rich in sound it could raise the hair on the back of your head.