Introduction
Anti-Mexican sentiment in the United States developed through a combination of inherited cultural prejudice and concrete conflicts over land, slavery, sovereignty, race, and national expansion. Raymund Paredes argues that Anglo-American attitudes toward Mexicans drew partly on older English images of Spain as Catholic, authoritarian, cruel, and culturally inferior, ideas sometimes grouped under the “Black Legend” (Paredes, 1977). During the nineteenth century, these religious stereotypes merged with racial theories that ranked Anglo-Saxon Protestants above Indigenous, African, Spanish, and mixed-race populations. Such ideas did not by themselves cause the Mexican-American War of 1846–1848. The conflict emerged from Texas colonization, slavery, the Texas Revolution, annexation, an unresolved boundary dispute, failed diplomacy, and the expansionist aims of President James K. Polk. Prejudice nevertheless shaped how many Americans interpreted those events, making Mexican sovereignty easier to dismiss and territorial conquest easier to portray as progress. A balanced history must therefore connect cultural attitudes with the political and economic struggles that made them consequential.
Inherited Prejudice and the Mexican Borderlands
Long before the Mexican-American War, Anglo-American political culture had inherited anti-Spanish and anti-Catholic assumptions from conflicts between Protestant England and Catholic Spain. English writers frequently portrayed Spain as exceptionally despotic or fanatical, while nineteenth-century U.S. nativism associated Catholicism with monarchical authority and foreign influence. After Mexico achieved independence in 1821, these inherited ideas were often transferred to an independent nation whose political life was in fact divided among federalists, centralists, liberals, conservatives, military leaders, clergy, regional elites, and ordinary citizens. Racial ideology added another layer. Because Mexico included Indigenous, European, African, and mixed populations, some American observers used prevailing racial hierarchies to characterize the country as inherently incapable of stable republican government. Paredes shows that this language predated many direct conflicts in Texas and helped frame later disagreements as evidence of cultural inferiority rather than as disputes between two sovereign political communities. The prejudice became especially influential when territorial ambition gave Americans a material reason to believe that Mexican land would be better governed under U.S. control.
The borderlands created the setting in which inherited stereotypes became attached to immediate political conflict. The Adams–Onís Treaty, signed in 1819 and ratified in 1821, transferred Florida from Spain to the United States and established a boundary that recognized Spanish control of Texas. When Mexico became independent, it inherited an enormous northern frontier with limited population, difficult communications, and substantial administrative costs. Mexican leaders therefore used colonization policy to attract settlers who could develop agriculture and strengthen the region. The General Colonization Law of 1824 allowed states to regulate settlement, and Coahuila y Texas offered generous land terms through empresario contracts such as Stephen F. Austin’s. Many migrants arrived from the United States but retained commercial and cultural ties across the border. Mexican officials increasingly worried that demographic growth by U.S. settlers could undermine national sovereignty, while some settlers viewed Mexican law, Catholic requirements, customs enforcement, and restrictions on slavery as unwanted interference. These competing expectations turned colonization from a development policy into a sovereignty problem (Weber, 1982).
Texas Colonization, Slavery, and Rising Sovereignty Conflict
Slavery was one of the most important differences between Mexico and many Anglo-American colonists in Texas. Migrants from the U.S. South brought enslaved African Americans into the region as they developed cotton agriculture, while independent Mexico moved gradually toward abolition. President Vicente Guerrero issued a decree abolishing slavery in most of Mexico in 1829, although Texas occupied a complicated legal position and settlers used exemptions and labor contracts to preserve slaveholding practices. The issue did not operate alone: colonists also disputed customs enforcement, immigration restrictions, local government, and the shift from Mexican federalism toward centralism. Yet slavery gave slaveholding settlers a direct economic reason to resist policies that threatened human property. The Fredonian Rebellion of 1826–1827 and the subsequent investigation by General Manuel de Mier y Terán increased Mexican fears that American settlement could lead to territorial loss. Those concerns contributed to the Law of April 6, 1830, which restricted immigration from the United States, strengthened customs and military controls, encouraged other settlement, and limited further introduction of enslaved people (Bishop, 2016).
The conflict cannot be reduced to a simple confrontation between all Anglo settlers and all Mexicans. Stephen F. Austin initially opposed the Fredonian Rebellion, many Tejanos supported federalism and later joined resistance to Antonio López de Santa Anna, and political disagreement existed throughout Mexico. The Constitution of 1824 had created a federal system, so Santa Anna’s movement toward centralization generated opposition in several regions, not only Texas. The Texas Revolution that began in 1835 therefore combined constitutional conflict, local autonomy, demographic change, slavery, and competing national identities. Some rebels initially claimed to defend the federal Constitution of 1824 rather than immediate independence. By March 1836, however, Texas had declared itself independent. The Battle of the Alamo became a powerful symbol of that struggle, and the executions at the Alamo and Goliad intensified hostility toward Santa Anna’s forces. Later popular memory often simplified the conflict into a racial narrative of heroic Anglos and villainous Mexicans, obscuring Tejano participation, Mexican opposition to centralism, and the importance of slavery in the new Republic of Texas.
Texas Independence, Memory, and the Unresolved Border
Texan forces under Sam Houston defeated Santa Anna at San Jacinto on April 21, 1836, and the captured Mexican president signed public and secret agreements at Velasco the following month. The agreements called for an end to hostilities and withdrawal of Mexican troops, while the secret terms contemplated Mexican recognition of Texas independence and a Rio Grande boundary. Mexico rejected the agreements on the grounds that Santa Anna had signed them while a prisoner and lacked authority to surrender territory under coercion. The Republic of Texas therefore existed independently in practice without a mutually accepted settlement with Mexico. Texas claimed the Rio Grande as its southern boundary, whereas Mexico regarded the Nueces River as the limit of Texas, leaving a large disputed zone between them. The United States recognized Texas in 1837 but delayed annexation for several years because annexation risked war with Mexico and intensified domestic controversy over adding another slaveholding state. The unresolved border later became central to the immediate military crisis that preceded the Mexican-American War.
Historical memory helped transform this unresolved political conflict into a broader cultural antagonism. The Alamo became a foundational story in Texas and U.S. popular culture, often emphasizing sacrifice and resistance to tyranny while giving less attention to Mexican federalists, Tejanos, the legal status of the rebellion, or slavery. Such narratives did not create anti-Mexican prejudice from nothing, but they could reinforce an image of Mexicans as a collective enemy. Paredes’s argument is valuable here because it connects memory to older stereotypes. The Black Legend, anti-Catholicism, and racial hierarchy supplied categories through which military episodes could be interpreted. Actions by Santa Anna’s army were sometimes generalized to Mexican people as a whole, while U.S. expansion was framed as the spread of republican civilization. The simplification mattered politically because public attitudes toward another nation affect how easily coercive policies can be justified. Cultural prejudice and material interests worked together: territorial ambition generated conflict, and negative stereotypes helped make that ambition appear morally legitimate to many supporters of expansion.
Manifest Destiny, Annexation, and the Road to War
The ideology later called Manifest Destiny gave American expansion a language of historical inevitability. The phrase became popular in 1845, but U.S. territorial growth had been underway for decades. Expansionists described continental growth as the spread of agriculture, commerce, republican institutions, and national security. These arguments often contained racial and religious assumptions that portrayed Indigenous peoples and Mexicans as obstacles to a supposedly superior civilization. Texas annexation brought those ideas into direct conflict with Mexican sovereignty. The United States annexed Texas in 1845 even though Mexico had never recognized the republic’s independence and had warned that annexation would be treated as hostile. President Polk also wanted California and New Mexico. He sent diplomat John Slidell to seek a settlement of the Texas boundary and negotiate territorial acquisition, but the Mexican government, facing intense domestic pressure, declined to receive him formally. Polk then ordered General Zachary Taylor’s forces from the Nueces area toward the Rio Grande, placing U.S. troops inside territory claimed by both governments (Office of the Historian, n.d.-b).
Mexican and U.S. forces clashed in the disputed region in April 1846. Polk told Congress that Mexico had shed American blood on American soil, while critics argued that the precise location of the clash and the prior troop movement made that description contested. Congress recognized a state of war on May 13, 1846 (Office of the Historian, n.d.-b). The war was controversial inside the United States. Whigs and antislavery politicians accused the administration of provoking conflict to seize territory and potentially expand slaveholding power. Abraham Lincoln’s later “Spot Resolutions” demanded that Polk identify the exact place where the first blood had been shed and establish that the site unquestionably belonged to the United States. These objections demonstrate that expansionism was powerful but not unanimous. The deeper causes of war included annexation, the boundary dispute, Polk’s desire for western territory, failed diplomacy, domestic political interests, and competing understandings of sovereignty. Anti-Mexican sentiment influenced how these issues were presented, but historical explanation requires distinguishing prejudice from the separate strategic and territorial objectives that also drove policy.
War, Treaty, and the Racial Politics of Conquest
U.S. forces invaded northern Mexico, occupied New Mexico and California, blockaded ports, and eventually captured Mexico City. The war ended with the Treaty of Guadalupe Hidalgo, signed on February 2, 1848. Mexico recognized the Rio Grande as the Texas boundary and transferred a vast area including present-day California, Nevada, Utah, New Mexico, most of Arizona and Colorado, and parts of other states. The Office of the Historian describes the cession as approximately 525,000 square miles, about 55 percent of Mexico’s prewar claimed territory, while the United States agreed to pay $15 million and assume specified claims held by U.S. citizens against Mexico (Office of the Historian, n.d.-b). The National Archives records treaty provisions concerning property and civil rights for Mexican nationals who remained in the transferred territories, although implementation proved uneven. The acquisition dramatically expanded the United States to the Pacific and immediately intensified national conflict over whether slavery would be permitted in the new western territories.
The end of formal war did not end racial and political inequality. Many Mexican residents remained in communities that had become part of the United States and later faced land loss, discriminatory taxation, legal costs, violence, segregation, exclusion from juries or political power, and stereotypes that treated them as foreigners despite longstanding residence in the region (Gómez, 2007). Treaty protections did not always prevent dispossession because property claims were contested through unfamiliar legal systems and expensive proceedings. The cultural narratives identified by Paredes continued to influence public life after military conquest. Mexicans and Mexican Americans were variously represented as bandits, passive laborers, political threats, or people incapable of self-government. These images interacted with labor demand, immigration policy, policing, and regional politics. The history therefore shows why prejudice should be studied together with institutions. Stereotypes become especially consequential when they help rationalize unequal access to land, citizenship, wages, legal protection, or political participation.
Conclusion
The origins of anti-Mexican sentiment in the United States lie in the interaction of inherited European prejudice and nineteenth-century struggles over territory, slavery, religion, race, and sovereignty. Anti-Spanish imagery, anti-Catholicism, and racial hierarchy shaped how many Anglo-Americans interpreted Mexico before direct conflict intensified in Texas. Colonization policy, the growth of U.S. settlement, slavery, the Law of April 6, 1830, Mexican federalism and centralism, and the Texas Revolution created a complex borderland crisis that cannot be reduced to cultural misunderstanding alone. The unresolved status of Texas and its boundary, U.S. annexation, Polk’s western ambitions, failed diplomacy, and military confrontation in disputed territory then led to the Mexican-American War. The Treaty of Guadalupe Hidalgo ended the war and transferred an enormous area to the United States, but Mexican residents in the ceded territories often faced discrimination and land loss afterward. Anti-Mexican sentiment was therefore not merely an attitude surrounding one war; it was a set of ideas that interacted with state power, territorial expansion, and the long-term construction of race and citizenship in the American Southwest.
References
Bishop, C. (2016). Law of April 6, 1830. Handbook of Texas. Texas State Historical Association.
Gómez, L. E. (2007). Manifest destinies: The making of the Mexican American race. New York University Press.
Greenberg, A. S. (2012). A wicked war: Polk, Clay, Lincoln, and the 1846 U.S. invasion of Mexico. Alfred A. Knopf.
Henderson, T. J. (2007). A glorious defeat: Mexico and its war with the United States. Hill and Wang.
Library of Congress. (n.d.). Independence from Spain to President Porfirio Díaz.
National Archives and Records Administration. (1848). Treaty of peace, friendship, limits, and settlement between the United States of America and the United Mexican States.
Office of the Historian. (n.d.-a). Acquisition of Florida: Treaty of Adams-Onís 1819 and Transcontinental Treaty 1821. U.S. Department of State.
Office of the Historian. (n.d.-b). The annexation of Texas, the Mexican-American War, and the Treaty of Guadalupe Hidalgo, 1845–1848. U.S. Department of State.
Paredes, R. A. (1977). The origins of anti-Mexican sentiment in the United States. New Scholar, 6, 139–165.
Weber, D. J. (1982). The Mexican frontier, 1821–1846: The American Southwest under Mexico. University of New Mexico Press.
Academic Master Education Team is a group of academic editors and subject specialists responsible for producing structured, research-backed essays across multiple disciplines. Each article is developed following Academic Master’s Editorial Policy and supported by credible academic references. The team ensures clarity, citation accuracy, and adherence to ethical academic writing standards
Content reviewed under Academic Master Editorial Policy.
