During the Mexican War, a group of Irish soldiers serving in the U.S. military switched sides to join the Mexican army and take up arms against U.S. Expansion into Mexican soil. They were called San Patricio's (St. Patrick's) Battalion. Here is a leaflet1 they printed explaining their cause, and appealing particularly to Catholics not to fight against others who shared their religion. The unusual capitalization is faithful to the original handbill.From Voices of A People's History, edited by Zinn and Arnove
CATHOLIC Irish, Frenchmen and German of the invading army!
The american nation makes a most unjust war to the mexicans, and has taken all of you as an instrument of their iniquity. You must not fight against a religious people, nor should you be seen in the ranks of those who proclaim slavery of mankind as a constitutive principle. The religious man, he who possesses greatness of mind, must always right for liberty and liberty is not on the side of those who establish differences in mankind, making an unhappy and innocent people, earn the bread of slavery. Liberty is not on the part of those who desire to be the lords of the world, robbing properties and territories which do not belong to them and shedding so much blood in order to accomplish their views, views in open war with the principles of our holy religion. The mexican people raises every where in order to wage an insurrectionary war, and that american army however large it may become, shall find here a grave. The mexican people wishes not to shed the blood of those who profess their own religion, and I, in the name of inhabitants of the state of Vera Cruz invite you to abandon those ranks to which you must not belong. I have given the necessary orders, so that, should you abandon them, you may be respected in all the towns and places of the states where you happen to go, and all the requisite assistance shall be given to all, till brought before me. Many of your former companions fight now content in our ranks. After this war is over, the magnanimous and generous mexican nation will duly appreciate the services rendered, and you shall remain with us, cultivating our fertile lands. Catholic Irish, French and German!! Long live Liberty!! Long live our holy Religion!!
1 Juan Soto, Desertion Handbill (June 6,1847). In Paul Foos, A Short, Offhand Killing Affair: Soldiers and Social Conflict During the Mexican-American War (Chapel Hill and London: University of North Carolina Press, 2002), p. 106. Original handbill in the Beinecke Rare Book and Manuscript Library, Yale University, New Haven, Connecticut.