The Mexican War of Independence: How Mexico Freed Itself from Spain

By the early 1800s, Spain was no longer a world power. Here’s a look at how its most prized colony, Mexico, finally won its freedom, in the Mexican War of Independence.

Dec 9, 2022By Owen Rust, MA Economics in progress w/ MPA

mexican war of independence


Beginning in 1521, following the defeat of the Aztecs, the Spanish began to colonize what is now Mexico. The Viceroyalty of New Spain, consisting of everything from modern-day Panama up through modern-day northern California, was a vast territory. Following successful revolutions in North America and France, common people in New Spain and its southern neighbors, the Viceroyalties of New Granada (modern-day northern South America), Peru, and Rio de la Plata (modern-day Argentina), wanted their own independence. When France seized control of Spain during the Peninsular War, revolutionaries in Spain’s colonies saw their chance to act. Over the course of a decade, revolutionaries in Mexico fought for freedom. The subsequent Mexican War of Independence began on September 16, 1810.


1520-1535: Viceroyalty of New Spain Created

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A map of New Spain circa 1750s, via the University of North Texas


After discovering the New World in 1492 and settling the Caribbean in the early 1500s, Spanish explorers landed in modern-day Mexico in 1519. The landing in southern Mexico coincided with Aztec prophecies that a god, Quetzalcoatl, would return. The similarities between Quetzalcoatl and Spanish conquistador Hernan Cortes made the Aztecs assume–at least temporarily–that he was the deity. The Spanish were invited into the Aztec capital, Tenochtitlan, where they began their efforts to overthrow the Aztec Empire.


The defeat of the Aztecs was swift, with the 500 or so Spanish soldiers aided by other Native American tribes and deadly smallpox. Smallpox ended up decimating the Native American population due to total lack of natural immunity, allowing the Spanish to colonize almost the entirety of South and Central America. With the approval of both the Holy Roman Empire and the Roman Catholic Church, Spain formally established the Viceroyalty of New Spain, centered around the former Aztec capital of Tenochtitlan, in 1535.


1500s-1800s: Slavery & Caste System in New Spain

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Conflict between Spanish soldiers and Native Americans in 16th-century New Spain via Brown University, Providence


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After conquering the territory that would become New Spain, the Spanish created an elaborate system of social classes, race-based castes, and forced labor. The encomienda system used Native Americans for forced labor during the early 1500s, although this was protested by Spanish priest Bartholeme de las Casas and rendered illegal by King Charles V in 1542. However, protests by encomenderos (Spanish royals in New Spain) led the king to revoke the law in 1545, allowing forced labor of Native Americans to continue.


By 1545, smallpox had killed many Native Americans, forcing the Spanish to transport slaves from Africa to the Caribbean and New Spain for labor. Therefore, the encomienda system was effectively replaced by African slavery. Over time, Spaniards intermarried with Native Americans, as did enslaved people from Africa. This created new demographics, which the Spanish placed into a hierarchical caste system. At the top of this hierarchy were full-blooded Spaniards who were born in Spain, known as Peninsulares. At the bottom were slaves from Africa, as Native Americans were technically considered subjects of Spain (even if they were performing forced labor).


1500s-1800s: Growing Mestizo Population

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A painting of a Spanish man and a Native American woman with a mestizo child, via Central New Mexico Community College, Albuquerque


Over time, the culture of New Spain became unique from Spain. Many Spaniards intermarried with Native Americans, which produced the mestizo caste, quickly becoming the most rapidly growing demographic in the colony. Although they adopted Spanish surnames, as almost all fathers of mixed-race children were Spaniards, they maintained at least some cultural traditions from their mothers’ lineage. As New Spain grew and expanded, mestizos began filling important roles, including in government. However, they were often treated as second-class citizens, especially in areas with larger Spanish populations.


The increasing mestizo population, along with a growing African slave and mulatto (mixed African and Spanish lineage) population, created an increasing divide between Spain and New Spain. This was especially true outside of Mexico City (formerly Tenochtitlan), where the Spanish tended to congregate, and mestizos and mulattos had greater social and economic opportunities as New Spain’s infrastructure expanded northward into the present-day American Southwest. Over 300 years, the growing mixed-race population of New Spain weakened socio-cultural ties with Spain.


1700s-1800s: Isolation of Criollos in New Spain

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South American revolutionary leader Simon Bolivar, seen in this painting, was a criollo born to Spanish parents, via Prairie View A&M University


The second tier of the caste system in New Spain consisted of criollos, those of full Spanish descent born in the colonies. Although they were of pure Spanish heritage, they were considered less noble than peninsulares. Quickly, resentments built between the two castes, with peninsulares often believing criollos to be inferior and criollos believing peninsulares to be opportunistic snobs seeking unearned land and titles in the colonies. Over time, however, criollos began to gain more power and wealth due to their status as merchants. Commerce overtook crown-given land grants as the ultimate source of wealth and prestige during the 1700s.


After the mid-1700s, the formal caste system became laxer, and criollos increasingly sought wealth and prestige internally, from within New Spain rather than from Spain itself. By the 1790s, the Spanish relaxed many of the formal caste identifications regarding military service. Part of this was by necessity, as peninsulares and wealthier criollos had little desire for military service. This allowed less wealthy criollos and even some mestizos to use military service as a source of gaining prestige and noble titles.


1807: France Seizes Spain in the Peninsular War

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A painting of Joseph Bonaparte, brother of French dictator Napoleon Bonaparte, who was installed as the new king of Spain during the Peninsular War, via Royal Central


Part of Spain’s relaxation of the formal caste system in its viceroyalties was out of necessity: it was no longer the same world power that had rapidly colonized South and Central America. After it failed to conquer England in 1588 with its massive Spanish Armada, Spain slowly ceded global power and prestige to France and England as they colonized North America. After the French and Indian War (1754-63), England was clearly the dominant power in Europe. Spain and France maintained an on-and-off alliance to try and check England’s power, which allowed France to surprise Spain with a sudden betrayal and seizure in 1807.


After the French Revolution (1789-94), military officer Napoleon Bonaparte emerged as the nation’s ruler in 1799 after a coup d’état. Within a few years, he embarked on a mission to conquer all of Europe for France, a goal opposed most strongly by England. After 1804, Napoleon decided to invade Portugal after the small country–which shared the Iberian Peninsula with larger Spain–defied France and continued to trade with England. After crafting a secret treaty with Spain that would divide Portugal between the two after its defeat, France sent its troops through Spain to invade Portugal by land. Then, in a surprise twist, Napoleon seized Spain and eventually placed his brother, Joseph Bonaparte, on the Spanish throne.


Spain In Turmoil Leads to Independence Movements

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British troops in Spain in 1813, via Royal Scots Dragoon Guards


Although Napoleon was able to quickly depose King Carlos IV of Spain in early 1808, there was strong Spanish resistance to being occupied by France. A revolt commenced, and Napoleon’s forces under General Dupont were handed one of their first military defeats in July 1808. The British quickly arrived in both Portugal and Spain to fight the French, resulting in a lengthy war. Napoleon responded by sending large armies to try to crush the “rebellion” in Spain and defeat the British, resulting in a historic feud between Napoleon and Britain’s Field Marshal Arthur Wellesley, later named Duke of Wellington.


With Spain completely embroiled in a European war, those in the viceroyalties of New Spain, New Granada, Peru, and Rio de la Plata who wanted independence had a prime opportunity. Inspired by recent successful revolutions in the United States and France, they desired self-rule and freedom from a rigid and oppressive monarchy. On September 16, 1810, a priest named Miguel Hidalgo y Costilla issued a call for independence. This date is today memorialized as Mexico’s Independence Day, when the Mexican War of Independence began. Similar independence movements began around the same time in South America, also taking advantage of Spain’s preoccupation with Napoleon’s forces.


The Mexican War of Independence Begins

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A painting of a battle during the Mexican War of Independence (1810-21), via the Texas State Historical Association


In the two years preceding Father Hidalgo’s declaration of independence, there had been division and distrust between criollos and peninsulares in New Spain regarding who should rule while Spain was effectively isolated by war. However, once the Mexican War of Independence began, criollos and peninsulares unified and became a powerful loyalist force. A new viceroy turned the tide on Hidalgo’s forces, which were mainly composed of Native Americans. The rebels fled north, away from Mexico City and toward the less-populated provinces.


In northern Mexico, government forces began to defect and ally with the rebels. However, this populist defection movement was short-lived, and within months the loyalists had regrouped. In March 1811, Father Hidalgo was captured and later executed. By August 1813, loyalists had regained control of even far-flung Texas, effectively defeating the first part of the Mexican War of Independence. Hidalgo’s successor, Jose Maria Morelos, formally declared independence from Spain and advocated democracy and an end to racial divisions. He was captured in 1815 and executed. During this period, independence movements in Venezuela, led by Simon Bolivar, were also unsuccessful.


1816-1820: Revolution Returns

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A painting of Agustin de Iturbide, the revolutionary who helped secure Mexico’s independence in 1821 and was briefly its first leader, via Memoria Politica de Mexico


Spain and England won the Peninsular War in 1814, and Napoleon was defeated in 1815. Free of the Napoleonic Wars, Spain could focus on its colonies. However, the return of the monarch and his strict policies upset many of the loyalists in the viceroyalties, as well as liberals within Spain. In March 1820, a revolt against Fernando VII forced him to accept the reinstatement of the Cadiz Constitution of 1812, which granted additional rights and privileges to those in the Spanish colonies.


Starting in 1816, Spain had begun to lose control of South America; it simply lacked the resources to reassert control, especially over its more distant colonies. In 1819, revolutionary Simon Bolivar declared the creation of the new nation Gran Colombia, encompassing modern-day Panama, Bolivia (named after Bolivar), Colombia, Ecuador, and Peru. However, in Mexico, it was the conservative Agustin de Iturbide, a former loyalist, who switched sides and joined with the revolutionaries to create the plan for an independent Mexico.


1821: Treaty of Cordoba Guarantees Independence

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Modern copies of the Treaty of Cordoba that granted Mexico’s independence, via The Catholic University of America, Washington DC


Iturbide and revolutionary leader Vincente Guerrero created the Plan of Iguala in early 1821. It upheld the power of the Catholic Church and gave criollos equal rights and privileges to peninsulares, removing much loyalist resistance to independence. Without the support of the criollo class, New Spain’s last viceroy had no choice but to accept Mexico’s independence. On August 24, 1821, the Treaty of Cordoba was signed and granted Mexico formal independence from Spain, thus ending the Mexican War of Independence.


A supporter of the monarchy system, Iturbide became the emperor of the First Mexican Empire after marching his army into Mexico City on September 27. The crowning of Iturbide occurred on July 21, 1822. The neighboring nation to the north, the United States, recognized the new nation in December. Mexico had become a sovereign nation, recognized by others as such.


1820s-1830s: From First Mexican Empire to Mexico

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A map of the First Mexican Empire circa 1822, via NationStates


The First Mexican Empire included all of Central America north of Panama, which was part of the new nation Gran Colombia. However, the lavish-spending Iturbide was swiftly opposed by middle-class criollo Antonio Lopez de Santa Anna, one of his lieutenants, and had to abdicate his throne in 1823. Provinces in Central America quickly declared their independence, forming the United Provinces of Central America. This became known as the Central American Federation. This dissolution ended the First Mexican Empire, and the United Mexican States, a more modern republic, was created in 1824.


During the 1820s, Spain did not recognize Mexico’s independence, despite the Treaty of Cordoba. On October 1, 1823, King Ferdinand VII declared that all treaties and acts signed since the Revolution of 1820 were null and void. In 1829, Spain attempted to re-invade Mexico, leading to the Battle of Tampico. Antonio Lopez de Santa Anna, who had retired to Veracruz after Iturbide resigned, defeated the Spanish and became a war hero. Only in 1836 did Spain finally accept Mexico’s permanent independence with the Santa Maria-Calatrava Treaty.


1836-1848: Continued Territorial Changes for Mexico

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A map showing Mexican territory lost in 1836 to the Republic of Texas, in 1848 to the Mexican Cession, and sold in 1853 with the Gadsden Purchase, via the Zinn Education Project


The early decades of Mexico’s independence were turbulent. On-again-off-again president Antonio Lopez de Santa Anna oversaw three significant losses of Mexican territory. In 1836, Mexico was forced to recognize the independence of the Republic of Texas, with Santa Anna signing a treaty as a prisoner taken in the Battle of San Jacinto. Texas later pursued statehood with the nearby United States of America, and annexation was completed in 1845. The very next year, Mexico and the United States engaged in warfare over disputed borders between the two countries. Mexico declared that Texas began at the Nueces River, while the US declared that it began further south and west, at the Rio Grande River.


Although brief, the Mexican-American War resulted in a tremendous loss of territory, over half for Mexico. The Mexican Cession gave the entire American Southwest, plus California, to the United States. Five years later, Santa Anna sold a final chunk of land in what is now southern Arizona and New Mexico to the United States. The Gadsden Purchase was made to buy land for a railroad, end lingering border disputes with Mexico, and allegedly raise money for Santa Anna himself. With this purchase, finalized in 1854, the continental borders of both the US and Mexico reached their current form.

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By Owen RustMA Economics in progress w/ MPAOwen is a high school teacher and college adjunct in West Texas. He has an MPA degree from the University of Wyoming and is close to completing a Master’s in Finance and Economics from West Texas A&M. He has taught World History, U.S. History, and freshman and sophomore English at the high school level, and Economics, Government, and Sociology at the college level as a dual-credit instructor and adjunct. His interests include Government and Politics, Economics, and Sociology.