In 1920, he aligned himself with fellow Sonoran revolutionary generals Adolfo de la Huerta and Álvaro Obregón to overthrow Carranza under the Plan of Agua Prieta. Carranza had attempted to choose an unknown civilian, Ignacio Bonillas, the Mexican ambassador to the U.S. as his successor. Carranza was forced out of power and died escaping, leaving De la Huerta as interim president. De la Huerta then named Calles to the important post of Minister of War.John Womack, Jr. "The Mexican Revolution" in Mexico Since Independence, Leslie Bethell, ed. New York: Cambridge University Press 1991, p. 195-96.
