The San Patricios

The San Patricios liked to sing “Green Grow the Lilacs”; it is said that the Mexican soldiers began to refer to their comrades as los greengros .

In early February a group of U.S. prisoners spotted swift-moving caissons, support troops double-timing behind the guns, and one of the captives was disgusted to see the guidon bearer “bearing aloft in high disgrace the holy banner of St. Patrick.” The San Patricios were on their way to Buena Vista, where on February 23, 1847, they fought Capt. John Paul Jones O’Brien’s D Battery, 4th U.S. Artillery. After breaking up a charge of the 1st U.S. Dragoons, O’Reilly then turned his fire on O’Brien. Within minutes the San Patricio “heavies” had silenced the U.S. six-pounders with fire so fast and accurate that it killed all of O’Brien’s horses and left most of his men dead or wounded. The captain had to abandon his last two intact pieces; some of O’Reilly’s outriders dragged them back to the Mexican lines.

But from this point the battle deteriorated steadily for the Mexicans. Santa Anna ordered an abrupt withdrawal, which turned into a rout late that afternoon, and Taylor hoped to smash him by nightfall. “But one Mexican battery continued its fire on our troops,” wrote the war correspondent John Bonner. “This was the 18- and 24-pounder battery of the Battalion of San Patricio, composed of Irishmen, deserters from our ranks, and commanded by an Irishman named Riley.”

Los soldados de San Patricio had helped open the battle, and now they were closing it. Two U.S. flying batteries under Capt. George Davis and Capt. Braxton Bragg skirmished cautiously with the better-armed San Patricios, but as night fell, Bonner reported, “the San Patricio Battery still commanded the southern edge of the plateau.”

The San Patricio Battalion lost twenty-two men in this stubborn, skillful rearguard action, and O’Reilly was promoted to captain. By late March he had a price on his head—U.S. authorities wanted him dead or alive- and the battalion was ordered south into action against Gen. Winfield Scott’s army, which had taken Veracruz and was driving overland toward Mexico City.

Every Mexican village and town the San Patricios marched through cheered them on their way to face Scott. Many of the men were redheaded, ruddy, and badly sunburned, and the Mexicans nicknamed them the Red Ones or los Colorados . A song that sprang up along the route was carried around the world as a sea chantey during the gold rush a few years later: “Santy Anna gained the day/Aweigh, Santy Anno / Zach’ry Taylor ran away / All on the plains of Mexico.” Another song and story are connected with the San Patricios: At day’s end they would sit around their campfires singing a song called “Green Grow the Lilacs.” The story goes that the Mexican sol- diers began to refer to their comrades as los greengros .

On April 18,1847, Los Gringos fought an impressive holding action in the mountains at Cerro Gordo. They were now heroes to the Mexicans, but they had suffered heavy casualties by this time, particularly among the new men. The professionals among them knew that Mexico was going to lose the war and that, as one of them wrote, “we fight with the halter around our necks.” On July 7, 1847, the officers of the San Patricios presented a document to their major, Francisco Moreno, a contract between the Mexican Army and “we, the undersigned foreigners of the Foreign Legion Companies of St. Patrick.”

It was a simple, straightforward paragraph that assured the San Patricios of their lands and bounties or relocation to a neutral country after the war. The document bore overtones that “Brave Reilli” had shown his true colors—as a mercenario —but he did have a responsibility to his men. Generals he trusted approved the contract, but it remained to be seen how many San Patricios would live to collect on its terms.

Quite a few of them died in the rugged fighting at Contreras on August 20. Throughout the day the U.S. forces made repeated charges against the Mexican positions, carried them at last, and recovered the two cannon O’Brien had lost at Buena Vista. In the lastditch fighting over those guns, eleven San Patricios were taken prisoner.