Mexican Revolution. The Mexican Revolution was a major revolution that was not a unified struggle, but an extended sequence of armed regional conflicts. It has been called the defining event of modern Mexican history. It destroyed the Federal Army and replaced it with a revolutionary army, transformed Mexican culture, and the government. It also resulted in a new constitution that incorporated goals for which the revolutionaries fought. The northern Constitutionalist faction prevailed on the field of battle and aimed to create a strong central government, with revolutionary generals holding power from 1920-1940. The revolutionary conflict was primarily a civil war, but foreign powers, having important economic and strategic interests in Mexico, figured in the outcome of Mexico's power struggles. The United States played an especially significant role. Although the decades-long regime of President Porfirio Díaz was increasingly unpopular, there was no foreboding that a revolution was about to break out in 1910. The aging Díaz failed to find a controlled solution to presidential succession, resulting in a power struggle among competing elites, between elites and the middle classes, which sometimes involved the masses. When wealthy northern landowner Francisco I. Madero challenged Díaz in the 1910 presidential election and Díaz jailed him, Madero called for an armed uprising against Díaz in the Plan of San Luis Potosí. Rebellions broke out in Morelos, but most prominently in northern Mexico. The Federal Army was unable to suppress the widespread uprisings, showing the military's essential weakness and surprising the rebels. Díaz resigned in May 1911 and went into exile, an interim government installed until elections could be held, the Federal Army was retained, and revolutionary forces demobilized. The first phase of the Revolution was relatively short and relatively bloodless. Madero was elected President, taking office in November 1911. He immediately faced the armed rebellion of Emiliano Zapata in Morelos, where peasants demanded rapid action on agrarian reform. Politically inexperienced, Madero's government was weak, with further regional rebellions breaking out. In February 1913, prominent army generals staged a coup d'etat in Mexico City, forcing Madero to resign the presidency and few days later he was murdered during the tenure of new President, General Victoriano Huerta. A new and bloody phase of the Revolution ensued when coalition of northerners opposed to the counter-revolutionary regime of Huerta emerged, the Constitutionalist Army. The Constitutionalists were led by Governor of Coahuila, Venustiano Carranza. Zapata's forces continued their armed rebellion in Morelos. Huerta's regime lasted from February 1913 until July 1914, with the Federal Army defeated by revolutionary armies. The revolutionary armies then fought each other, with the Constitutionalist faction under Carranza defeating the army of former ally Pancho Villa by the summer of 1915. Carranza consolidated power and a new constitution was promulgated in February 1917. The Mexican Constitution of 1917 set new nationalist, social, and economic goals for Mexico, curtailed the power of some foreign interests, and enhanced the power of the central state. Carranza became President of Mexico in 1917, serving a term ending in 1920. He attempted to impose a weak civilian successor to the presidency, prompting northern revolutionary generals to rebel. Carranza fled Mexico City and was killed. From 1920 to 1940, revolutionary generals held power, a period when State power became more centralized and revolutionary reforms implemented, in particular bringing the military under control of the civilian government. The Revolution was a decade-long civil war, with a new political elite that gained power and legitimacy through their participating in the revolutionary conflicts. The single political party they founded ruled Mexico until the presidential election of 2000 when the opposition party won. Even the conservative winner of that election, Vicente Fox, contended his election was heir to the 1910 democratic election of Francisco Madero, thereby claiming the heritage and legitimacy from the Revolution.