Saint Patrick's Battalion - Historical Perspective

Historical Perspective

For Americans of the generation that fought the Mexican-American War, the San Patricios were considered traitors. For Mexicans of that generation, and generations to come, the San Patricios were heroes who came to the aid of fellow Catholics in need.

The great majority of these men were recent immigrants who had arrived at northeastern U.S. ports, part of the Irish diaspora then escaping the Great Irish Famine and extremely poor economic conditions in Ireland, part of the United Kingdom of Great Britain and Ireland at the time. The U.S. Army often recruited Irishmen and other immigrants into military service shortly or sometimes immediately on arrival., with promises of salaries and land after the war.

Numerous theories have been proposed as to their motives for desertion, including cultural alienation, mistreatment of immigrant soldiers by nativist soldiers and senior officers, their not being allowed to attend Sunday Mass or to practice their religion freely, the incentive of higher wages and land grants starting at 320 acres (1.3 km2) offered by Mexico, and their witnessing poor conduct of U.S. troops following battle victories.

Some historians believed a primary motivation was shared religion with the Mexicans and sympathy for the Mexican cause, likely based on similarities between the situations in Mexico and Ireland. This hypothesis is based on evidence of the number of Irish Catholics in the Battalion, the letters of Jon Riley, and the field entries of senior officers. Another hypothesis is that the members of the Saint Patrick's Battalion had been unhappy with their treatment in the U.S. Army. Another theory some historians hold is that the soldiers were attracted by the valuable incentives offered by the Mexican government: higher wages and generous land grants. For poor people coming from famine conditions, economics was often an important incentive.

Mexican author José Raúl Conseco noted that many Irish lived in northern Texas, and were forced to move south due to regional insecurity. Early in the war they helped Gen. Taylor attack the fort and supply depot in St. Isabel, now the city of Port Isabel, Texas.

Irish expatriates had a long tradition of serving in military forces of Catholic countries, for instance, serving with Spain and later France in groups of young men who had left Ireland during what would become known as the Flight of the Wild Geese in the 17th century. In addition, many Irish fought as soldiers in South American wars of independence.