248 Mexican Revolution (1910–1920) Plan of San Luis Potosí, a reformist document calling for a return to the principles of the 1857 constitution In May 1911 the combined forces of Madero, Pascual Orozco, and Pancho Villa defeated Díaz’s federal troops in the border city of Ciudad Juárez In accord with the provisions of the Treaty of Ciudad Juárez, Díaz resigned; his foreign secretary, Francisco León de la Barra, became interim president (May–November 1911) On October 1, 1911, Madero was elected president He served for 15 months (November 1911–February 1913) His presidency was largely a failure, his moderate reforms placating neither hardline Porfiristas nor agrarian radicals like Zapata and Orozco On February 18, 1913, Madero was overthrown by one of his leading generals, the conservative Victoriano Huerta, following the the Decena Trágica (Tragic Ten Days), a destructive battle in Mexico City between Porfiristas and Maderistas—an overthrow made possible by the “Pact of the Embassy” between Huerta and U.S ambassador Henry Lane Wilson Huerta, reputed for his cruelty and hard drinking, ruled for the next 17 months (February 1913–July 1914) His regime, whose policies garnered the animosity of the United States, was overthrown by the constitutionalists under Venustiano Carranza following the U.S occupation of the port city of Veracruz, which had begun on April 21, 1914 The three years following Huerta’s ouster were the most chaotic of the revolution, with several major and scores of minor armies wreaking havoc across the country The most prominent figures included Pancho Villa and Pascual Orozco in the north; Zapata in the south; and the constitutionalists Carranza, Plutarco Calles, and Alvaro Obregón In December 1914 Villa and Zapata briefly occupied Mexico City Five months later—in April 1915—came the most famous military engagement of the war: the Battles of Celaya (in the state of Querétaro, April 6–7 and 13–15), in which Villa’s cavalry, estimated at more than 25,000 strong, was nearly destroyed by Obregón’s entrenched forces (Obregón was a keen student of European trench warfare) The battles’ outcome heralded the rising fortunes of Carranza and the constitutionalists Villa, his army severely weakend, retreated northward After the United States recognized Carranza as Mexico’s legitimate head of state in October 1915, Villa staged a series of anti-U.S reprisals, most famously his raid of Columbus, New Mexico, on March 9, 1916, in which his forces killed 18 U.S citizens and looted and burned the town The United States responded with Pershing’s Punitive Expedition, in which General John J Pershing led some 6,000 U.S troops into the northern Mexi- can deserts in pursuit of Villa The expedition, which cost $130 million, failed and withdrew from Mexico in January 1917 Meanwhile, in the south the Zapatistas continued their guerrilla campaign against the Carranza government, which had not endorsed Zapata’s Plan of Ayala demanding agrarian reform In November 1916 Carranza and the constitutionalists, entrenched in Mexico City, convened a constitutional convention in the city of Querétaro Excluding Villistas, Zapatistas, Huertistas, and others, the meetings eventually produced the constitution of 1917, which governs Mexico to the present day In March 1917 Carranza was elected president of Mexico, an office he assumed on May Several months earlier, in January 1917, Carranza had been approached by the German ambassador with a proposal to ally with Germany in a war against the United States (following his instructions in the famous Zimmermann Telegram, sent January 16, 1917, by the German foreign secretary Arthur Zimmermann) Carranza refused the offer, but the telegram, intercepted by the British, is often cited as hastening U.S entry into World War I With the formation of a constitutional, U.S.recognized government in Mexico City, the most violent years of the revolution were drawing to a close While fighting still raged across much of the country, by this time many Mexicans had wearied of the violence In the south the Zaptistas put up a stiff resistance against Carrancista forces sent down to suppress their armies In early 1919 Carranza dispatched a hit squad to Morelos to assassinate Zapata, which it did on April 10 A year later, on May 21, 1920, Carranza himself fell to an assassin’s bullet, leaving the presidency open to Obregón, one of whose allies had pulled the trigger When the revolution began in 1910, Mexico was home to an estimated 15 million people; 10 years later that number had dropped to an estimated 14 million In other words, between and million Mexicans died during this “age of violence,” while an additional quarter million or more migrated north to the United States—marking the origins of many MexicanAmerican communities in major U.S cities like Detroit, Chicago, and others After 1917 the revolutionary regime, dominated by elites from the northern state of Sonora (especially Obregón, Calles, and Adolfo de la Huerta), entrenched itself in power Through the 1920s the revolutionary state became increasingly institutionalized and its policies increasingly conservative It retained power despite frequent flare-ups of violence, most notably the Cristero Revolt of 1926–29, sparked by the Catholic Church’s disgruntlement with the