[4] Tyrone Power stars as the scrappy Irish immigrant whose 50-year career at West Point took him from a dishwasher to a non-commissioned officer and athletic instructor.

[5] Maureen O'Hara, one of Ford's favorite leading ladies, plays Maher's wife and fellow immigrant, Mary O'Donnell.

The film co-stars Ward Bond as Herman Koehler, the Master of the Sword (athletic director) and Army's head football coach (1897–1900), who first befriends Maher.

Philip Carey plays (fictional) Army football player and future general Chuck Dotson.

The phrase "The Long Gray Line" is used to describe, as a continuum, all graduates and cadets of the United States Military Academy at West Point, New York.

Many of the scenes in the film were shot on location at West Point, including the so called "million dollar view" [6] of the Hudson River near the parade grounds.

Facing forced retirement, Master Sergeant Martin Maher goes to the White House to appeal to the commander in chief, West Point graduate, and 5-star general, President Dwight D. Eisenhower, who gives Marty a warm welcome and listens to his story.

The Koehlers advise Mary not to engage in conversation with Marty until he re-enlists and proposes, for fear their two fiery Irish tempers will clash.

Over time, Marty earns the love and respect of men such as Omar Bradley, James Van Fleet, George Patton, and Dwight D. Eisenhower (to whom he gives advice on slowing hair loss).

Marty introduces cadet "Red" Sundstrom, who is struggling with math, to a post school teacher, Kitty Carter.

On Sunday, December 7, 1941, the church service is interrupted by the news of Japanese raid on Pearl Harbor and the United States' likely entry into World War II, Red confesses to Marty that he was married over Thanksgiving weekend.

Deeply disappointed, Marty is filled with pride when Sundstrom does the honorable thing by resigning and enlisting in the Army.

[7] Bosley Crowther of The New York Times called the film sentimental but a rich and rousing tribute to West Point, and likens Power's Martin Maher to "Mr. Chips with a brogue.