The Saint Patrick’s Battalion (Batallón de San Patricio), formed and led by John Riley (Seán Ó Raghailligh) from Clifden, Co. Galway, was a unit of 175 to several hundred immigrants and expats of European descent who fought as part of the Mexican Army against the United States in the Mexican-American War of 1846–8. Most of the battalion’s members had deserted from the United States Army.
The Battalion served as an artillery unit for much of the war. Despite later being formally designated as two infantry companies, it still retained artillery pieces throughout the conflict. The “San Patricios” were responsible for the toughest battles encountered by the United States in its invasion of Mexico, with Ulysses S. Grant remarking that “Churubusco proved to be about the severest battle fought in the valley of Mexico”.
Composed mainly of Catholic Irish emigres, the battalion also included Canadians, Germans, French, English, Poles, Italians, Scots, Spaniards, Swiss and Mexican citizens, many of whom were members of the Catholic Church. Some disenfranchised Americans were in the ranks, including escaped slaves from the Southern United States.
The San Patricios are revered and honoured in Mexico and Ireland. Members of the Battalion are known to have deserted from various U.S. Army regiments including; the 1st Artillery, the 2nd Artillery, the 3rd Artillery and the 4th Artillery, to name but a few.
It can be said that the Irish, when abroad, seemed to like to side with the underdog, whether it was in Mexico, France, Scotland, Chile, Argentina or Spain. Sadly there is a lot of Irish blood that has been spilled in foreign lands, when perhaps it might have been better for such brave men to have died in the arms of Roisín Dubh, in the fight for Irish freedom.