Showdown at Abilene (Gun Shy) (1956)

Jim Trask, former sheriff of Abilene, returns to the town after fighting for the Confederacy to find everyone thought he was dead. His old friend Dave Mosely is now engaged to Trask's former sweetheart and is one of the cattlemen increasingly feuding with the original farmers. Trask is persuaded to take up as sheriff again but there is something about the death of Mosely's brother in the Civil War that is haunting him.