The moment the Stars and Stripes was raised over Chapultepec Castle on September 13, 1847, thirty Irish deserters were hanged.

In a clever campaign to convince immigrant soldiers to switch sides, the Mexicans urged their Catholic brothers to turn against the “Protestant tyrants.”  Santa Anna soon had enough Irish deserters to create the San Patricio Battalion that fought bravely in several battles.  But those captured by the Americans faced long prison sentences or death on the gallows.