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 Infantería Guadalajara nº 20 is a Spanish infantry regiment that fought in America. Battle included the Siege of Pensacola (1781).
Source(s): http://peter.mackenzie.org/history/hist51.htm, Image: Durero (wikipedia),