South of St. Louis

South of St Louis is a 1949 Western film directed by Ray Enright. Starring Joel McCrea, the film chronicles the friendship between three ranchers after their ranch is destroyed by raiders led by the infamous Luke Cotrell. The movie was originally titled Distant Drums, but was later changed to its current title, a term that refers to Civil War army deserters.

As they attempt to cross the border, they run into Cottrell and his gang. In the ensuing gunfight, Kip and Charlie are saved by a company of Confederate soldiers led by Lee, one of which is Lee. The three return to Edenton, where Kips fiancee again attempts to convince him to stay. Kip is determined, however, to get enough money to restart his farm and instead continues to smuggle guns. When Brownsville is finally captured by rebel soldiers, the three must decide what the next course of action is. Lee continues to fight with the Confederate army, Kip wants to restore Three Bell ranch, and Charlie, more interested in the money, opts to continue smuggling guns. When Deborah refuses to leave her duties as a nurse to join him at the ranch, Kip decides to go with Charlie and return to smuggling. This pleases Rouge, who has fallen in love with Kip.As they near the border, they get word that Cottrell has threatened to kill Charlie and Kip if they return to Matamoros. At Slims suggestion, they decide to steal the shipment of guns before it even reaches Mexico. The men dress up as Union soldiers in order to steal the guns, but then run into Confederate soldiers who confuse them for the enemy and open fire. Lee, who suspects that Kip and Charlie are behind the attack, breaks off all connections with his two former friends. ........

Source: Wikipedia