Only the Valiant (1951)

Directed by William Cagney

Capt. Richard Lance (Gregory Peck) is unjustly held responsible, by his men and his girlfriend (Barbara Payton), for an Indian massacre death of beloved Lt. Holloway. Holloway (Gig Young) is killed while escorting a dangerous Indian chief to another fort's prison. The chief escapes. Knowing their fort is in danger of Indian attack, Lance takes a small group of army misfits to an abandoned nearby army fort to defend a mountain pass against the oncoming Indian assault. Their mission is to stall for time until reinforcements from another fort arrive.