“…it was St. Patrick, the Harp of Erin, the Shamrock upon a green field” – John Riley, Saint Patrick's Battalion and the Mexican–American War

12 September 1847, Condemned as traitors for fighting the US Army as Batallón de San Patricio or Saint Patrick's Battalion after deserting American ranks during the Mexican–American War, 50 men, mainly Irish, were hanged in and around Mexico City, an event commemorated in Mexico and elsewhere on this day as the generally accepted anniversary date of the executions.

“Bring the damned son of a bitch out! My order was to hang 30 and by God I'll do it!“ (Col William Harney, 2nd Dragoons, US Army, on Francis O'Connor of the San Patricios who had lost both his legs in the Battle of Churubusco and was subsequently court-martialled.)

Soldier, painter and author Samuel E. Chamberlain’s (1829 – 1908) imagination of the mass hangings around 12 September 1847 (c. 1867)

It was more than a decade before regiments of both sides marched into the battles of the US Civil War with the fifes, drums and bagpipes playing Irish tunes and men of all kinds of origins sang songs like “The Minstrel Boy” or “The Rising of the Moon”. When the green flags of the “Irish Brigade” were rolled out after the regiment was ordered to be the next to die on the muddy slope leading up to the sunken road on Marye’s Heights west of Fredericksburg, one of the men of the 24th Georgia Infantry, almost completely made up of Irish as well, cried out: “Oh God, what a pity! Here comes Meagher's fellows." They mowed down the Irish of the "Fighting Sixty-Ninth" from New York just like Hancock’s and French’s brigades none the less. Back in 1846, when the US declared war on Mexico to follow Polk’s “Manifest Destiny”, Irishmen were already recruited right after they stepped from the coffin ships that had brought them across the Atlantic, away from the hunger and discrimination back home in Ireland. Usually, the Catholic Irish were welcomed in the Regular Army with a mixture of disgust and sadistic glee by their officers against the background of rampant American nativism and strong anti-Catholic sentiment. And while the 160,000 Irishmen fighting for the Union in the Civil War certainly changed public opinion about the Irish, “the wretched of the Earth” from Ireland that came to America during the first half of the 19th century, working on the canals and the railroads or getting drafted into the US Army got a treatment of prejudice and discrimination almost as bad as that of non-Caucasian ethnic or racial groups. It was one of the main reasons for the high desertion rate of especially Irish-born troops during the Mexican-American War, and, along with the promise of higher pay, better treatment, full citizenship and a land grant in staunchly Catholic Mexico, to join the ranks of Generalissimo Santa Ana. And one such group was formed as one of the most successful military units Mexico fielded in the war, the Batallón de San Patricio, the Saint Patrick's Battalion, led by John Riley.

Contemporary depiction of Major General Zachary Taylor's Army of Occupation
fighting green-coated Mexicans during the Battle of Buena Vista in February 1847,
possibly the San Patricios

John Riley hailed from Clifden in County Galway, was born around 1818, did his turn in the British Army, possibly in Canada, and did not return home when the Great Famine broke out in Ireland in 1845. Riley ended up in the US Army and deserted from James McIntosh’s 5th Infantry Regiment after crossing the Rio Grande near future Fort Texas, just a few days before war was finally declared on 25 April 1846. The treatment of Irish regulars by nativist officers certainly played a major role in his decision, Mexican promises of money, citizenship and land, already in place for experienced soldiers, might have been an additional motivation as well as sympathy for the Catholic Mexicans and the Mexican cause. During the Battle of Monterrey, the one fought in Nuevo León in Northeastern Mexico in September 1846, the San Patricios had their first appearance as artillery unit, made up from elements of the former “Legión de Extranjeros”, something of a Mexican Foreign Legion. Commanded, at least de facto, by John Riley, half of the seven hundred San Patricios came from Ireland or were Americans of Irish origin, the other half were Catholics from Germany and Poland, Italians and what not, usually with a military background gained in the US and various European Armies. Reorganised as a mixed artillery and infantry unit under a green silk banner, woven and embroidered by the nuns of San Luis Potosí, remarked upon by Riley as “ that glorious Emblem of native rights, that being the banner which should have floated over our native Soil many years ago, it was St. Patrick, the Harp of Erin, the Shamrock upon a green field.” And while the Mexican army was pushed back to the outskirts of Mexico City until mid-September 1847 with the San Patricios fighting bravely in most battles, sometimes threatening to shoot their own comrades if they wouldn’t stand fast, it was to no avail. Riley and his men fought their last fight as Batallón de San Patricio during the Battle of Churubusco on 20 August 1847. Finally forced to surrender, the battalion, already down to 200 men, had 35 dead and 85 captured, Riley among them. Seventy-two were immediately charged with desertion by the US Army.

Eye-witness Carl Nebel's recollection of the Battle of Churubusco

Riley was lucky in so far as he got off the hook with a thorough flogging and branding of the letter “D” for “deserter” on both cheeks, since he ran before war was officially declared, 50 of the San Patricios were treated and sentenced as traitors, to be hanged and not shot as spies or deserters. It became the largest mass execution in United States history, effected in three instalments, the first on September 10th on San Jacinto Plaza, the next on the following days, and while the local populace begged Winfield Scott to have mercy with the San Patricios, the US commander on the spot staged the hanging of the last 30 of them, wounded or not, in full view of Chapultepec Castle on 13 September, the men dropped precisely at the moment after the stronghold surrendered, the Mexican flag went down and “Old Glory” went up the flag pole. The “Mártires Irlandeses”, the Irish martyrs for Mexican independence, those who survived the war and especially those who were executed in Mexico City are well remembered and worshipped as heroes to this day, with two days of remembrance, one on 17 March, St Patrick’s Day, the other on 12 September, the generally accepted anniversary date of the executions. The existence of the San Patricios was hushed up until 1915 in the US since Winfield Scott made his run for the presidency in 1852 and his opponents tried to sway Irish-American voters with the tale and afterwards for not to encourage desertion. Today, Mexico’s only Bagpipe Band, the “Banda de Gaitas del Batallon de San Patricio” is inducted into the Irish America Hall of Fame and the San Patricios are at least remembered on both sides of the Rio Grande in song, story and various movies. John Riley himself probably died in 1850 in Veracruz and was buried there under the name of Juan Reley, “of forty five years of age, a native of Ireland, unmarried, parents unknown; died as a result of drunkenness, without sacraments“. His native Clifden, however, flies a Mexican flag on 12 September, to commemorate him and the San Patricios.

A plaque commemorating the San Patricios

And more about the Batallón de San Patricio on: