On this St. Patrick’s Day, let us pause to remember a piece of history that has been taboo in the United States: St. Patrick’s Batallion.  Wikipedia explains:

The Saint Patrick’s Battalion (Spanish: Batallón de San Patricio) was a unit of 175 to several hundred immigrants (accounts vary) and expatriates of European descent who fought as part of the Mexican Army against the United States in the Mexican-American War of 1846 to 1848. Most of the battalion’s members had deserted or defected from the U.S. Army. Made up primarily of ethnic Irish and German Catholic immigrants, the battalion also included Canadians, English, French, Italians, Poles, Scots, Spaniards, Swiss, and native Mexicans, most of whom were also Roman Catholics. Disfranchised Americans were also in the ranks, including African Americans who had escaped from slavery in the American South. The Mexican government offered incentives to foreigners who would enlist in its army: it granted them citizenship, paid higher wages than the U.S. Army and gave generous land grants. None of the members of the Saint Patrick’s Battalion, except for a few Americans, had yet become a U.S. citizen.

I found this pacificfreepress.com blog post very helpful in trying to undertand the historical context of this (to read the entire post follow this link):

During the buildup to the Mexican-American War (1846-8), scores of immigrant Irishmen joined the army for the $7 a month. “The U.S. anti-immigrant press of the time caricatured the Irish with simian features, portraying then as unintelligent and drunk and charging that they were seditiously loyal to the pope,” Anne-Marie O’Connor wrote in the Los Angeles Times …  

“But cheap Irish labor was welcome. Irish maids became as familiar as Latin American nannies are today.” Harsh treatment did not end after the Irishmen enlisted in the armed forces. “Anglo soldiers often harassed them, beat them up,” said Robert Ryal Miller, author of Shamrock and Sword.

After President James Polk incited hostilities by sending U.S. troops into disputed territory…and many of those Irish soldiers who found themselves heading west to fight a war of conquest were Catholic. “This is a story about assimilation,” historian Peter F. Stevens adds. “A lot of these guys deserted because of the anti-Catholic, anti-foreigner movement.”

This obscure piece of history is a fascinating one; The Los Angeles Times has previously pointed out that the story of St. Patrick’s Army could very well represent:

[…] an allegory for the plight of immigrants, a morality tale on the implacability of Manifest Destiny, and an example of the bond of Irish-Mexican solidarity in an era of increasing mutual trade.

Happy St. Patrick’s Day everyone … and don’t forget about the Batallón de San Patricio when you’re drinking your Guinness tonight 😉