The Mexican Revolution was the first major social revolution of the 20th century. Its causes included, among others, the authoritarian rule of dictator Porfirio Díaz, the seizure of millions of acres of indigenous village lands by wealthy hacendados and foreign investors, and the growing divide between the rich and the poor. As a result of these varied causes and Mexico’s strong social and regional divisions, the revolution against Díaz lacked ideological focus. The revolutionaries ousted Díaz within six months but could not agree on the new social and political order and—after a failed attempt at democracy—ended up fighting among themselves in a bitter civil war. In 1917, the victorious Constitutionalist faction crafted a landmark constitution, the first in the world to enshrine social rights and limit the rights of private, and particularly foreign capital. Although never fully implemented and partially repealed in the 1990s, the document remains the most significant achievement of the revolution. After 1920, a succession of revolutionary generals gradually centralized political power until the election of a civilian presidential candidate in 1946. This effort at state building confronted significant resistance from popular groups, regional warlords, and disaffected leaders who had lost out in the political realignment. In the end, the symbolic significance of the revolution exceeded its political and social outcomes.
While fundamentally agrarian in nature, the revolution thus ultimately produced a new national elite that gradually restored a strong central state. One can easily divide the revolution into a military (1910–1917) and a reconstructive phase (1917–1946). However, the latter phase witnessed an important generational shift that transferred political power from the leaders of the military phase to their subordinates as well as civilian representatives, with the formation of a revolutionary ruling party in 1929 serving as the most important watershed moment in this process. Therefore, this essay distinguishes among three separate phases: insurrection and civil war (1910–1917); reconstruction (1917–1929); and institutionalization (1929–1946).