Mexico Gains Independence from Spain

After more than a decade of brutal fighting and over 20,000 casualties, Mexico officially gained its independence from Spain on September 27, 1821. This moment marked the end of three centuries of Spanish rule. The road to independence, however, was long, complicated, and filled with both triumphs and setbacks.

Spain had controlled Mexico since 1521, when Spanish conquistador Hernán Cortés defeated the Aztec Empire and claimed the territory for Spain. For centuries, Spain governed Mexico as a colony and extracted wealth through mining and agriculture, while enforcing a rigid social hierarchy that favored Spaniards born in Europe. People born in Mexico of Spanish ancestry, called creoles, had limited power compared to their European counterparts, and Indigenous and mixed-race people were often treated as second-class citizens. For many years, this system remained mostly unchallenged. But by the early 1800s, events in Europe changed everything.

In 1808, Napoleon Bonaparte invaded Spain and forced King Ferdinand VII to abdicate the throne. This left Spanish colonies across the Americas in political turmoil, creating an opportunity for independence movements to rise. In Mexico, the push for independence began with a priest named Miguel Hidalgo y Costilla.

On the night of September 15–16, 1810, Hidalgo rang the church bells in the town of Dolores and called for an uprising against Spanish authorities. This historic speech became known as the Grito de Dolores, or “Cry of Dolores,” and is celebrated every year as the start of Mexico’s War of Independence. By morning, Hidalgo had gathered a growing army of Indigenous peasants and mestizos (people of mixed Indigenous and European heritage) who were determined to overthrow Spanish rule.

The rebel army marched to Guanajuato, an important mining city controlled by Spaniards and creoles loyal to the crown. The defenders barricaded themselves inside the city’s granary, but the rebels stormed the building on September 28, capturing it and killing or exiling most of those inside. This victory was a major early success for the independence movement, but it also shocked the Spanish authorities and convinced them to strike back hard.

Just a month later, on October 30, Hidalgo’s forces fought the Spanish army at the Battle of Monte de las Cruces. Although the rebels initially gained ground, they were unable to take Mexico City. Many survivors were forced to retreat and go into hiding. The movement suffered another devastating blow in January 1811, when Spanish troops defeated the rebels at the Battle of the Bridge of Calderón. Hidalgo and several other leaders attempted to flee toward the US-Mexico border but were captured, put on trial, and executed later that year.

Despite the loss of Hidalgo, the fight for independence did not end. Leadership passed to José María Morelos, another Catholic priest and skilled military commander. Under Morelos, the rebels regrouped and captured key cities, including Oaxaca and the important port of Acapulco. In 1813, Morelos convened the Congress of Chilpancingo, where revolutionary leaders drafted a constitution and signed the Solemn Act of the Declaration of Independence of Northern America on November 6, formally declaring Mexico’s independence.

Unfortunately, Morelos was captured in 1815 and executed by Spanish forces, leaving the independence movement leaderless once again. For the next several years, small groups of guerrilla fighters kept the cause alive, slowly wearing down Spanish control.

Finally, in 1821, the independence movement found success under the leadership of Agustín de Iturbide and Vicente Guerrero, who united royalist and rebel forces under the Plan of Iguala. This agreement promised independence, equality between Spaniards and creoles, and the protection of Catholicism. On September 24, 1821, Spanish representatives signed the Treaty of Córdoba, officially recognizing Mexico’s independence. Three days later, the Army of the Three Guarantees triumphantly entered Mexico City, bringing an end to 11 years of conflict and establishing Mexico as a free and independent country.

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