When the United States invaded Mexico in the 1840s, the objective was westward expansion into territory that was sparsely settled, inspired by a movement called Manifest Destiny, the belief that the United States was destined by God to dominate the entire continent. During that same period, nearly a million Irish would migrate to the New World. They were fleeing famine in their own country, as well as a repressive British government that saw Irish deaths as a way to control the unruly Celtic people, who they viewed as locked into a Catholic religion that the Anglo-Protestant majority found regressive and intolerable.

The Irish, for their part, had no idea when they came to America that their religion and Celtic race would label them as inferior. Nor did they realize that the only work for them, in those tight economic times, would be as soldiers in an army poised to invade their southern neighbor. By the time most of them woke up to that reality, they found themselves in Texas, on the Mexican border. Abused, forced to attend Protestant religious services, and singled out for punishments, they were often whipped and branded for minor offenses. Once at the Rio Grande, where they could hear church bells from just across the river, a group of them, led by a crack artilleryman named John Riley, deserted the Americans and joined forces with the Mexicans.  

Within a year, the ranks of Riley’s men were bolstered by Catholic foreigners within Mexico into a battalion known as the“San Patricios.” They fought under a green silk flag emblazoned with the Mexican coat of arms, an image of St. Patrick, and the words “Erin Go Bragh.”  The addition of veteran gunners to the Mexican side resulted in two major battles being fought to a draw.  Irishmen were awarded the Cross of Honor by the Mexican government for their bravery, and many received field promotions.

At the Battle of Churubusco in August 1847, holed up in a Catholic monastery and surrounded by a superior force, the San Patricios withstood three major assaults. Eventually, however, a shell struck their stored gunpowder, the ammunition park exploded and, after a gallant counteroffensive with bayonets, they found themselves overwhelmed by sheer numbers. 

In September 1847, the Americans put the captured Irish soldiers on trial.  Forty-eight were sentenced to death by hanging.  Those who had deserted before the declaration of war were sentenced to whipping at the stake, branding, and hard labor.  

At dawn on September 13, 1847, some days after the first group of 18 had been executed, an American colonel ordered the remaining Irishmen to be brought to a hill in Mixcoac a few kilometers from Chapultepec Castle, where the final battle of the war was being fought.   Finally, the Americans scaled the walls of the castle, tore down the Mexican flag, and raised the Stars and Stripes.  With that, the colonel drew his sword and gave the order for execution.  After four hours of standing bound and hitched in 90 degree heat, the remaining 30 men were finally launched into eternity.

Spurred by Manifest Destiny and racial and religious animosity, the American government dictated terms to the Mexicans in the Treaty of Guadalupe Hidalgo in 1848.  The Americans took more than two-thirds of all Mexican Territory. This included Texas, what would become the states of California, Nevada, New Mexico, Arizona, Utah, and Wyoming, as well as parts of Kansas and Colorado. Among all the wars fought by the United States, the Mexican War is the least discussed in the classroom, and the least known by the general public.  Yet, it added more to the national repository, and to the landmass of the United States than all other wars combined.

For most Mexicans, solidarity with the Irish is part of a long tradition.  People of both countries share an emphasis on the spiritual center residing in the family and a non-materialistic frame of reference, in which a person’s worth is determined not by what he possesses, but by the quality of his life.  And, if Paddy and Bridget were considered incapable of being assimilated into an Anglo-Protestant society, their acceptance into Mexican society was seamless.  In the words of John Riley, written in 1847, but equally true today,  “A more hospitable and friendly people than the Mexican there exists not on the face of the earth . . . especially to an Irishman and a Catholic.”

Riley sums up what cannot be documented clearly in any history: the basic, gut-level affinity the Irishman had then, and still has today, for Mexico and its people. The courage of the San Patricios, their loyalty to their new cause, and their unquestioned bravery forged an indelible seal of honor on their sacrifice. Their memory will long be honored by the people of Mexico.

Photo credit: Lucinda Mayo.