Obregón, Álvaro (älˈvärō ōbrāgōnˈ) [key], 1880–1928, Mexican general and president (1920–24). A planter in Sonora, he supported Francisco I. Madero in the revolution against Porfirio Díaz. In 1913, Obregón joined Venustiano Carranza in the overthrow of Victoriano Huerta and later was commander against the opponents of Carranza, especially Francisco Villa. One of the most enlightened generals in the revolution, he was for a time Carranza's minister of war. When the latter attempted to perpetuate himself in power, Obregón promptly led a successful revolt (1920). After the provisional administration of Adolfo de la Huerta, Obregón became president. The revolutionary program became official during his administration and advanced out of confusion and blood into a recognizable if not thoroughgoing system of agrarian and labor reforms; peonage was still rampant. The most significant achievement of the Obregón regime was the educational program advanced by José Vasconcelos. The United States delay (until 1923) in recognizing his regime was due mainly to proclamations by certain self-styled radicals urging, among other things, the nationalization of oil deposits. Obregón was involved in a long, bitter quarrel with the church. His government was gravely challenged when de la Huerta was persuaded by opponents of Plutarco Elías Calles, Obregón's presidential candidate, to lead a revolt (1923–24). In 1928, Obregón was again chosen president, but before taking office he was assassinated by a fanatical Roman Catholic. He wrote Ocho mil kilómetros en campaña (1917), recollections of his campaigns.