The name pays tribute to the Saint Patrick's Battalion, made up of Irishmen and other European immigrants to the United States who defected and fought on the side of the Mexican army in the Mexican-American War of 1846–1848. The Cantina is where Post used to be (in Post Alley), the ownership is Irish (of the Kells family), and the drinks include lots of tequila-based cocktails, an "Irish martini"—Jameson, Grand Marnier, and lime—and other stuff from all over the place (the menu is on-the-pricey-side Mexican).