Editing Saint Patrick's Battalion (section)

===Formation and early engagements===
Present in the Mexican Army for the battles of [[Battle of Palo Alto|Palo Alto]] and [[Resaca de la Palma]] were the ''Legión de Extranjeros'' (Legion of Foreigners); the men who would later make up the core of the Saint Patrick's battalion. Meanwhile, deserters were abandoning General Taylor's army on the [[Rio Grande]].{{sfn|Grant|1998|p=115}} Riley and "a company of 48 Irishmen"{{sfn|Stevens|1999|p=291}} manned Mexican artillery at the [[Siege of Fort Texas]], which took place concurrently to the two other battles. [[Martin Tritschler]], [[German Mexican]] and a Captain at the [[Battle of Cerro Gordo]], is attributed with convincing a large number of German soldiers to defect from the U.S. occupying forces in [[Puebla, Puebla]].

The first major engagement of the Saint Patrick's Battalion, as a recognised Mexican unit, was as an [[artillery battery]] in the [[Battle of Monterrey]] of 21 September 1846.{{sfn|Newark|2012|loc="The first significant battle for the San Patricios was at Monterrey on 21 September 1846"}}{{sfn|Tucker|Arnold|Wiener|2013|loc=p. 197: "The battalion was formed as an artillery company and fought at Matamoros and Monterrey"}} Popularly they were called ''Los Colorados'' by the Mexicans because of their ruddy, sun-burnt complexions and red hair color.{{sfn|Wallace|1950|p=85}}{{sfn|Bauer|1992|p=42}} They were commanded by [[John Riley (soldier)|John Riley]],{{Ref label|B|b|2}} an Irishman who had previously served in the [[British Army]] as a [[non-commissioned officer]] and possibly arrived in Canada in 1843 whilst serving in his British unit (the assertion that Riley was a [[sergeant]] in the [[66th (Berkshire) Regiment of Foot]]{{sfn|Wallace|1950|p=85}} is known to be inaccurate).{{sfn|Miller|1989|p=27}} Riley went on to join the U.S. Army in Michigan in September 1845. He deserted in Matamoros in April 1846.{{sfn|Hogan|1998|p=42}} Upon meeting Mexican forces he was initially given the [[Officer (armed forces)|Officer]] rank of [[Lieutenant]] by [[General]] [[Pedro de Ampudia]].{{sfn|Hopkins|1913|p=280}}
[[File:Monterey U.S.S Grantp114.jpg|thumb|170px|left|{{lang|es|San Patricios}} defended the city of Monterrey with artillery fire from its citadel, indicated here with the key "F".{{Ref label|D|d|none}}]]

At the battle of Monterrey the {{lang|es|San Patricios}} proved their artillery skills by causing the deaths of many American soldiers, and they are credited with defeating two{{sfn|Howes|2003|p=181}} to three{{sfn|Callaghan|1995}} separate assaults into the heart of the city. Among their targets were companies led by such officers as [[Braxton Bragg]], many of whose soldiers would end up in their own ranks later in the war.{{sfn|Stevens|1999|pp=150 & 172–173}} Their tenacity, however, did not affect the Mexican commanders' decision to capitulate and abandon the position.

Following the engagement at [[Monterrey]], the {{lang|es|San Patricios}} grew in number, by some estimates reaching an enlistment of over 700 men.{{sfn|Hopkins|1913|p=280}}{{sfn|Chamberlain|1853|p=226}} Forces re-assembled at [[San Luis Potosí]] and they had their distinct green silk flag embroidered there.<ref>{{cite web |title=The San Patricio Battalion |url=http://themedalhound.com/sanpatricio/ |website=the medal hound |access-date=25 May 2024}}</ref>