http://www.latinamericanstudies.org/mex-war/mexico-ireland.htm So we deserted and fought against the US in this one battle but we also gave mexico Zorro (yep he was irish) and one of ours founded Tucson (The future capital of Baja Arizona)
"William Lamport, born in 1615, was one of many Irishmen who became famous in Mexico for his adventurous life. The story tells us that a scandalous love affair caused him to flee to Mexico (Nueva Espa ña), where he was moved by the poverty and degradation of Indians and Africans. Ultimately, he was accused of plotting a war of independence against the government, which led to his imprisonment. After ten years, he escaped and lived as a fugitive, continuing his life and love affairs in the New Spain. Eventually, he was captured and sentenced to death by the Inquisition, launching his name into legendary martyrdom. At the time, his adventurous and charitable lifestyle had such an impact, that citizens dubbed him the famous "El Zorro."(1)
Another prominent Irishman who had a hand in Mexican politics was Dublin-born Hugh O'Connor, who moved to Nueva Espa ña to escape the harsh conditions that reigned in Ireland at that time. In his adopted homeland, he became one of the most notable bureaucrats, taking office as governor of the region of Texas and commander of the northern frontier. He was also the founder of the town now known as Tucson, Arizona. In the18th century, several bureaucrats and officers who represented Spain in Mexico were either Irish, or of Irish descent. O'Connor was one of the most important and distinguished.(2)