Pancho Villa signs a treaty with the United States, halting border conflicts.
The Pancho Villa Expedition—now known officially in the United States as the Mexican Expedition, but originally referred to as the "Punitive Expedition, U.S. Army"—was an unsuccessful military operation conducted by the United States Army against the paramilitary forces of Mexican revolutionary Francisco "Pancho" Villa from March 14, 1916, to February 7, 1917, during the Mexican Revolution of 1910–1920.
The expedition was launched in retaliation for Villa's attack on the town of Columbus, New Mexico, and was the most remembered event of the Mexican Border War. The declared objective of the expedition by the Wilson administration was the capture of Villa. Despite locating and defeating the main body of Villa's command, responsible for the raid on Columbus, U.S. forces were unable to achieve Wilson's stated main objective of preventing Villa's escape.
The active search for Villa ended after a month in the field when troops sent by Venustiano Carranza, the head of the Constitutionalist faction of the revolution and now the head of the Mexican government, resisted the U.S. incursion. The Constitutionalist forces used arms at the town of Parral to resist passage of a U.S. Army column. The U.S. mission was changed to prevent further attacks on it by Mexican troops and to plan for war in the eventuality it broke out. When war was averted diplomatically, the expedition remained in Mexico until February 1917 to encourage Carranza's government to pursue Villa and prevent further raids across the border.