Villa subsequently led a raid against a small U.S.-Mexican border town resulting in the Battle of Columbus on 9 March 1916, and retreated to escape U.S. retaliation. The U.S. government sent U.S. Army General John J. Pershing on an expedition to capture him, but Villa continued to evade his attackers with guerrilla tactics during the unsuccessful nine-month incursion into Mexican sovereign territory. The mission ended when the United States entered World War I and Pershing was recalled to other duties.