During the Texas War of Independence of 1836 American frontiersman and pioneer Jim Bowie pleads for caution with the rebellious Texicans. They don't heed his advice since he's a Mexican citizen, married to the daughter of the Mexican vice-governor of the province and a friend to General Santa Anna since the days they had fought together for Mexico's independence. After serving as president for 22 years, Santa Anna has become too powerful and arrogant. He rules Mexico with an iron fist and he would not allow Texas to self-govern. Bowie sides with the Texans in their bid for independence and urges a cautious strategy, given Santa Anna's power and cunning. Despite the disagreement between the Texicans and Bowie regarding the right strategy they ask Bowie to lead them in a last-ditch stand, at Alamo, against General Santa Anna's numerically superior forces.

Childhood chums Rocky Sullivan and Jerry Connelly grow up on opposite sides of the fence: Rocky matures into a prominent gangster, while Jerry becomes a priest, tending to the needs of his old tenement neighborhood.