In 1914, following the resignation of Mexican leader Victoriano Huerta, Pancho Villa and his former revolutionary ally Venustiano Carranza battled each other in a struggle for succession. By the end of 1915, Villa had been driven north into the mountains, and the U.S. government recognized General Carranza as the president of Mexico.
In January 1916, to protest President Woodrow Wilson's support for Carranza, Villa executed 16 U.S. citizens at Santa Isabel in northern Mexico. Then, on March 9, 1916, Villa led a band of several hundred guerrillas across the border and raided the town of Columbus, killing 17 Americans. U.S. troops pursued the Mexicans, killing 50 on U.S. soil and 70 more in Mexico.
On March 15, under orders from President Wilson, U.S. Brigadier General John J. Pershing launched a punitive expedition into Mexico to capture Villa dead or alive. For the next 11 months, Pershing, like Carranza, failed to capture the elusive revolutionary and Mexican resentment over the U.S. intrusion into their territory led to a diplomatic crisis. On June 21, the crisis escalated into violence when Mexican government troops attacked Pershing's forces at Carrizal, Mexico, leaving 17 Americans killed or wounded, and 38 Mexicans dead. In late January 1917, having failed in their mission to capture Villa and under pressure from the Mexican government, the Americans were ordered home.
Villa continued his guerrilla activities in northern Mexico until Adolfo de la Huerta took power over the government and drafted a reformist constitution. Villa entered into an amicable agreement with Huerta and agreed to retire from politics. In 1920, the government pardoned Villa, but three years later he was assassinated at Parral.