My Darling Clementine (1946)

In the middle of a long cattle drive, Wyatt Earp (Henry Fonda) and his brothers stop off for a night in the town of Tombstone. The next morning they find their cattle stolen, and one of the brothers is dead. Earp suspects the Clanton family, owners of the O.K. Corral, but wants his revenge to be legal. He becomes sheriff of Tombstone and forges a rough peace with an alcoholic gambler, Doc Holiday (Victor Mature). Earp also takes a liking to Holiday's former girlfriend, Clementine (Cathy Downs).