How & When Mexico Became a Country: Independence from Spain

Mexico's birth as a sovereign nation was an 11-year armed struggle followed by a brief imperial experiment.

The War of Independence (1810–1821)

• Grito de Dolores: Sep 16, 1810 — Father Miguel Hidalgo y Costilla calls for revolt in Dolores, Guanajuato.
• Phases: Hidalgo (1810–11) → Morelos (1811–15) → Guerrilla stalemate (1815–20) → Iturbide's Plan de Iguala (1821) unites royalists & insurgents.
• Key leaders: Hidalgo, Morelos, Guerrero, Guadalupe Victoria, Iturbide.

Formal Independence

• Treaty of Córdoba: Aug 24, 1821 — Spanish viceroy Juan O'Donojú recognizes independence.
• Army of Three Guarantees enters Mexico City: Sep 27, 1821.
• Declaration of Independence of the Mexican Empire: Sep 28, 1821.

First Government: Empire, Then Republic

Key Date

September 27, 1821 — Effective independence (Army enters capital).
September 16 — National holiday (Grito anniversary), not independence day.