During the American Revolution Spain supported the American cause with supplies. They were was also at war with Britain at the time and engaged in battles around the world, including America. Regimiento de la Milicia de San Luis de Ultramar is a Spanish infantry regiment that fought in America. Battles included Baton Rouge (1779), Mobile (1780), and the Battle of St. Louis (1780).
Source(s): http://peter.mackenzie.org/history/hist51.htm, Image: Durero (wikipedia),