The Mexican Revolution was brought on by a major armed struggle that started in 1911, among other factors, with an uprising led by Francisco I. Madero against longtime autocrat Porfirio Díaz. The Revolution was characterized by several socialist, liberal, anarchist, populist, and agrarianist movements. Over time the Revolution changed from a revolt against the established order to a multi-sided civil war. There was less fighting after 1920, when Álvaro Obregón, the most important revolutionary leader still alive, became President.
During that span, power was concentrated in the hands of a select few; the people had no power to express their opinions or select their public officials. Wealth was likewise concentrated in the hands of the few, and injustice was everywhere, in the cities and the countryside alike.