One Man's Hero tells the little-known story of the "St. Patrick's Battalion" or "San Patricios," a group of mostly Irish and other immigrants of the Catholic faith who deserted to Mexico after encountering religious and ethnic prejudice in the U.S. Army during the Mexican-American War. The plot centers around the personal story of John Riley, an Irishman who had been a sergeant in the American Army who is commissioned as a captain in the Mexican army and commands the battalion, as he leads his men in battle and struggles with authorities on both sides of the border
as Captain John Riley
as Cortina
as Marta
as Col. Benton Lacy
as Corporal Kenneally
as Paddy Noonan
as Brian Athlone
as Cpl. Schultz
as Seamus McDougherty
as Daniel Grzbalski
as General Winfield Scott
as General Zachary Taylor
as Dominguez
as Captain Gaine
as Seamus Fitzgerald
as McFadden
