Mexican Independence

Mexican independence was achieved in 1821, when a coalition of former royalists and longtime insurgents brought roughly three centuries of Spanish rule in New Spain to an end. The outcome mattered far beyond Mexico: it removed Spain's richest and most populous mainland colony from its empire, reshaped the balance of power in North America, and opened a long, turbulent search for a stable national government.

The roots of the break lay in the Spanish colonial order, which privileged peninsular-born Spaniards over American-born creoles and left mestizos, Indigenous peoples, and people of African descent at the bottom of a rigid hierarchy. Napoleon's invasion of Spain in 1808 shattered the legitimacy of imperial authority and set off debates over who should govern in the king's absence. In 1810 the priest Miguel Hidalgo issued the Grito de Dolores, launching a mass uprising that drew heavily on rural and Indigenous support. Hidalgo was captured and executed in 1811, and José María Morelos carried the movement forward until he met the same fate in 1815. By the late 1810s, the insurgency had dwindled into guerrilla warfare, with Vicente Guerrero holding out in the southern mountains.

The decisive shift came from Spain itself. In 1820 a liberal revolt forced King Ferdinand VII to restore the Constitution of 1812, alarming conservative elites in New Spain who feared reforms that might curb the Church and their own privileges. Agustín de Iturbide, a royalist officer who had fought the insurgents, was sent to defeat Guerrero but instead negotiated with him. In early 1821 he proclaimed the Plan of Iguala, which promised three guarantees: independence, the primacy of the Catholic faith, and equality and union between Americans and Europeans. The Army of the Three Guarantees formed from the alliance, and Spanish resistance quickly collapsed.

The last viceroy-designate, Juan O'Donojú, arrived and signed the Treaties of Córdoba in August 1821, recognizing Mexican sovereignty, though the Spanish government later rejected them. Iturbide's army entered Mexico City in late September, and independence was declared soon afterward. A provisional government followed, and the new state was initially conceived as a constitutional monarchy.

That monarchy proved short-lived. Iturbide was proclaimed emperor in 1822, but he faced opposition from republicans and military rivals and abdicated in 1823. Mexico then became a federal republic under the Constitution of 1824. The decades ahead brought political instability, economic strain, foreign intervention, and the loss of vast northern territories to the United States in the 1840s. Spain did not formally recognize Mexican independence until 1836.

Historians continue to debate the nature of 1821, with some stressing its conservative character as an elite settlement and others emphasizing the long insurgent struggle that made it possible. Mexico today commemorates independence on September 16, honoring Hidalgo's call to arms in 1810 rather than Iturbide's later triumph.