Plot
A stagecoach races across the Southwestern desert, carrying widower Lieutenant Colonel Owen Thursday and his daughter, Philadelphia, to his new posting at Fort Apache, an isolated U.S. cavalry post on the Arizona frontier. Thursday is impatient and full of complaints, revealing little understanding of the country. A West Point graduate who was brevetted a general during the Civil War, he has been serving in Europe for several years and is full of resentment at being recalled and “shunted aside” to what he considers a career-ending assignment.
At a waystation, they meet newly minted graduate Second Lieutenant Michael O'Rourke on his way to Fort Apache. Four sergeants arrive with a vehicle to meet Michael, which irks Thursday. The sergeants notice that Michael and Philadelphia are attracted to each other. They arrive at Fort Apache during the Washington's Birthday dance. Philadelphia dances with acting commander Captain Kirby York. York commanded his own regiment during the Civil War and has learned the ways of the Apache. Michael has a touching reunion with his parents.
The next morning at officers call, Thursday assumes command and criticizes them all—except for Michael—for being improperly dressed, revealing a by-the-book approach that soon establishes him as a martinet. When York tries to brief him on the realities of life at Fort Apache, Thursday dismisses Native Americans as “digger Indians”.
Michael is the son of highly regarded Sergeant Major Michael O'Rourke, the post's ranking non-commissioned officer. The elder O'Rourke was a major in the Irish Brigade during the Civil War and earned the Medal of Honor, entitling his son to enter West Point and be commissioned an officer. Thursday is taken aback by this revelation.
Michael takes Philadelphia riding, and they encounter the burned corpses of two men sent to repair the telegraph wires. They race back to Fort Apache. Thursday forbids Michael Philadelphia's company. He sends Michael and a small detail—the sergeants “volunteer”— to retrieve the bodies and repair the wire. York objects until Thursday follows this up with an order to muster a large force to follow on Michael's heels. The trap works and the attacking Native Americans are killed or beaten off.
York advises Thursday to treat the tribes with honor and to remedy problems on the reservation of malnutrition, alcoholism and decay caused by corrupt Indian agent Silas Meacham. An inspection of Meacham's store reveals alcohol, rifles, and shoddy goods. Thursday steps on the scale used to weigh beef rations and observes he has gained a lot of weight. Thursday tells Meacham he would hang him if it were within his power, but duty requires him to protect the man as a representative of the United States government.
At a dinner party with the O’Rourkes, Colonel Thursday interrupts only to be told by Lt O’Rourke that he is in love with Philadelphia. She agrees to be married, but the colonel forbids it.
Cochise has moved into Mexico, fleeing starvation and abuse. Thursday wants to be the man who brings the Apaches back. York successfully negotiates for peace with Cochise, who returns to American soil, but Thursday, eager for a military victory, musters the entire regiment to ride against the Apache.
Outnumbered four to one, Thursday agrees to meet with Cochise, whose allies include Geronimo. Deaf to Cochise's eloquent statement, Thursday promises to attack the next morning. York tells Thursday attacking in columns of fours would be suicidal. Thursday orders York to take Michael and stay back with the supply train. Thursday charges directly into Cochise's trap. Wounded and separated from his men, Thursday refuses a rescue from York and instead returns to die with the remnants of his command. Cochise spares York and the soldiers who did not participate in the battle.
Several years later, Thursday has come to be regarded as a hero. Entertaining some correspondents, Regimental Commander Colonel York says nothing to tarnish the legend. He adds that those who died that day will never be forgotten as long as the regiment lives. He leads the regiment off after Geronimo.
