Saint Patrick’s Day is the day people see as an excuse to drink or to pinch those who forgot to wear green. Beyond that, though, is a chance to learn something about our home, California, and the rest of the American South West for that matter. There was a time when these lands were ruled under Mexican law. The process of turning them American involved a controversial war between the United States and Mexico, in which America took about half of Mexico’s vast territories.
Irish immigrants, who were Catholic and victims of oppression under British rule, were drafted to join the Army to invade Mexico. Some of them questioned the legitimacy of the war, and after an act of courage, or some might say, foolhardy rashness, they switch sides and fought for the Mexican state.
Picture yourself in their shoes. Imagine leaving your home island, wrecked by famine and imperial rule from England, migrating to a hostile United States, joining their armed forces, and then being forced to be the oppressors to a nation of fellow Catholics. If you already lost your nation, your family, and the respect of those around you simply for being Irish, wouldn’t you find desertion easy, especially when it’s for a cause you relate to? Perhaps this internal struggle was the main cause of the Irish American soldiers (though some were also from other countries) to switch sides and help Mexico in its war of self defense.
The reasons are still debated today, but among them are their mistreatment under the American officers, the promises of land that the Mexican government made them, and a solidarity to Catholicism.
They were the strongest and bravest fighters, threatening friendly fire on any soldier who would not stand up and fight against the U.S. in the heat of battle, and are remembered to this day.
I recommend you continue to look into this interesting piece of history that is often overlooked. Library books, websites, and documentaries are great sources. I also recommend you see the movie One Man’s Hero (1999). The following is a clip from the movie.