"RIDE WITH BUCK...BACK TO THE DANGER-JAMMED DAYS WHEN THE WEST WAS REALLY WILD!"

White Eagle (1941)

Serials usually spawned feature film versions, but with this film, it was the other way around. A 1932 Buck Jones Western, White Eagle was made into a serial nine years later, again starring Jones in the title role, a (supposedly) Native American Pony Express Rider defending his people against a gang of evil Whites.

Columbia Pictures