Latin America. Early Irish involvement in South and Central America was a by‐product of the employment of Catholic Irishmen in the service of the Catholic powers of Europe. Don Ambrosio O'Higgins (
c.1720–1801), marquis de Osorno, born Ambrose Higgins, probably in Co. Sligo, went first to Spain and then to South America, where he became a successful military commander and colonial administrator. He was governor of Chile 1787–95 and viceroy of Peru 1795–1801. His natural son Bernardo O'Higgins (1778–1842), educated in England, led the successful Chilean struggle for independence against Spain and headed the first national government 1817–23. Meanwhile the
United Irish veteran John Devereux (1778–1860) had raised an Anglo‐Irish legion of 5,500 men, about half of whom were Irish, to support the revolt of the Spanish American colonies. The legion, strongly endorsed by Daniel
O'Connell, whose teenage son Morgan was an officer on Devereux's staff, saw action in Simon Bolivar's war of liberation in Venezuela. During the Mexican–American war of 1846–8 a St Patrick's Battalion composed of some 200 Irish deserters from the United States army fought on the Mexican side.
One Latin American country, Argentina, provided a minor destination for Irish
emigration during the 19th century, receiving a total of around 7,000 settlers up to 1870, and another 3,600 by 1895. The prominence among these settlers of migrants from Cos. Westmeath, Longford, and Wexford suggests a classic pattern of chain migration, in which existing settlers encouraged and assisted the arrival of relatives and former neighbours. Up to
c.1870, Irish settlers were in many cases able to build up substantial cattle ranches in a rapidly expanding economy; thereafter this type of spectacular upward mobility became more difficult to achieve.