Major Frank Tompkins had led about 120 men of the 13th Cavalry deep into Mexico in pursuit of Villa when Carrancista soldiers turned on them in Parral. Tompkins conducted a fighting withdrawal to the village of Santa Cruz de Villegas. Two Americans were killed and six wounded, including Tompkins, while Mexican losses were reported at between fourteen and seventy killed or wounded. Parral marked the expedition's deepest point in Mexico, 516 miles from the border.
After Pancho Villa's forces crossed the border and raided Columbus, New Mexico in March 1916, killing 18 Americans, President Woodrow Wilson authorized General John J. Pershing to lead more than 10,000 troops into Mexico in pursuit — the last major U.S. cavalry campaign and an early proving ground for motorized vehicles and aircraft in American warfare.
The expedition, however, quickly became a diplomatic minefield. Mexican President Venustiano Carranza had never authorized American troops on Mexican soil and viewed the deepening incursion as a violation of sovereignty, regardless of shared antipathy toward Villa. Clashes between American cavalry and Carranza's own federal troops, rather than Villa's guerrillas, became increasingly common as Pershing's men pushed farther south, the first and most serious of them at Parral on April 12, 1916.
The expedition never captured Villa, who used his knowledge of the terrain and support among local populations to evade the Americans for nearly a year, becoming something of a folk hero in the process. Pershing withdrew in early 1917, partly because tensions with Germany were pulling American attention toward the looming entry into World War I — a conflict where Pershing himself would soon command the entire American Expeditionary Force.
Key people: Pancho Villa, John J. Pershing, Venustiano Carranza, Frank Tompkins