Convincing and realistic is “The Iron Major.” Pat O’Brien‘s new film proves to be a surprisingly entertaining film that is a well deserved tribute to a great American – the late Major Frank Cavanaugh. Cavanaugh was a Massachusetts boy who, at Dartmouth, Holy Cross, Boston College, and Fordham, became one of the greatest football coaches of all time, and who on the battlefields of France in 1918  became one of the nation’s heroes. Ruth Warrick plays Cav’s loyal wife and Robert Ryan the coach’s former teammate.