High Quality Content by WIKIPEDIA articles! The Battle of St. Louis (Spanish San Luis, also known as the Battle of Fort San Carlos) was an unsuccessful British-led attack on St. Louis (a French settlement in Spanish Louisiana that had been ceded by France to Spain in 1763) on May 26, 1780, during the American Revolutionary War. A force composed primarily of Indians and led by a former British militia commander attacked the settlement. The settlement`s defenders, mostly local militia under the command of Lieutenant Governor of Spanish Louisiana Fernando de Leyba, had fortified the town as best they could, and successfully withstood the attack.