The Long Gray Line is a 1955 American Technicolor drama film in CinemaScope directed by John Ford based on the life of Marty Maher. 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. Maher was buried there in January 1961. Wikipedia
Jim O'Carberry: This is Marty Maher. Whitey Larson.
Martin 'Marty' Maher: How do you do, sir?
Jim O'Carberry: If you have any trouble with horses, drop around and see Marty.
Whitey Larson: But he's in the infantry!
Jim O'Carberry: Well naturally! He knows horses. You don't think they'd put him in the cavalry, do ya?