Vera Cruz (1954)

Two nineteenth century soldiers of fortune, one survivor of the Civil War with a soft spot for sick horses and social justice, the other a charming and greedy trigger-happy killer, search for their next dollar down in Mexico at a time when the country is torn between Emperor Maxmillian and the nationalist peasant Army trying to overthrow him. Since the Emperor has the most cash, our hired guns agree to serve the Emperor by escorting a Countess to the city of Vera Cruz by passing through territory under rebel control. On the way to Vera Cruz, both fighters discover three million U.S. dollars in gold coins (intended to buy guns for the Emperor from France) hidden at the bottom of the stagecoach carrying the Countess, and she is not totally unaware of the fact either. She has her own plans too. All three plot against the other two to scoop the treasure away. Betrayal is not an issue. It's not even personal. It's just business. After a few gunfights and ambush scenes between Maxmillian's escorting Army and the peasant rebels, justice reigns, and Ben Trane emerges as the noble soul who triumphs over crass materialism despite the soft spot in his heart that Joe Erin took for weakness.

IMDb: https://www.imdb.com/title/tt0047647