The Guns of Fort Petticoat (1957)

Texan and U.S. Cavalryman Lt. Frank Hewitt (Audie Murphy) deserts the army after Colorado Union soldiers carry out the deadly Sand Creek reservation massacre, fearing reprisal from the Cheyenne. Crossing into Texas, Franks finds himself labeled a traitor for fighting with the Yankees, and his warnings about possible Indian revenge go unheeded. When a town near a mission, populated mostly by women, is attacked, Frank is appointed their protector and must build an army comprised of townswomen.