In the closing phases of the First Seminole War (1817-1818), Creek Indians attacked a U.S. supply boat ascending the Escambia River from Pensacola in Spanish West Florida to Fort Crawford in the American Alabama Territory. The attack prompted Major White Young at Fort Crawford to launch an April 1818 assault by American forces into Spanish West Florida against several Creek encampments on Bayou Texar, only a mile from Pensacola. With no Creek warriors present to protect them, Young's assault resulted in the massacre of around 30 Creek women and children. This massacre partially prompted U.S. Army General Andrew Jackson to march his troops westward from St. Marks, and in May 1818 Jackson captured Pensacola and the Spanish fortifications, bringing an end to the major military events in the war and convincing Spain of the futility of holding onto their colony of Florida.