The Treaty of Guadalupe Hidalgo ended the Mexican-American War and reshaped North America. It forced Mexico to give up half its land, including California and Texas, to the U.S. for $15 million. The treaty also set the Rio Grande as the new border.

For Mexicans living in the ceded territories, the treaty offered a choice: become U.S. citizens or move to Mexico. However, those who stayed often faced discrimination and land loss, despite promises of equal rights. This led to ongoing struggles for civil rights and recognition.

Treaty of Guadalupe Hidalgo

Provisions of Guadalupe Hidalgo Treaty

• Officially concluded the Mexican-American War (1846-1848) and established peace between the two nations
• Required Mexico to surrender a vast portion of its northern territory to the United States, encompassing the present-day states of California, Nevada, Utah, and parts of Arizona, New Mexico, Colorado, and Wyoming
• Obligated the United States to provide Mexico with a payment of $15 million as compensation for the acquired territory
• Designated the Rio Grande as the new international boundary between Texas and Mexico, resolving the disputed border claims
• Offered Mexican citizens residing in the ceded territory the choice to either become U.S. citizens or relocate to Mexico
• Committed the United States to actively prevent and combat Native American incursions and raids into Mexico originating from the newly acquired territory

Border changes from treaty

• Resulted in Mexico losing roughly half of its pre-war territory, estimated to be around 525,000 square miles of land
• Substantially expanded U.S. territory, extending the nation's reach from the Atlantic Ocean to the Pacific Ocean
• Redefined the border between the United States and Mexico, with the Rio Grande River serving as the new boundary separating Texas from Mexico
• Further modified the border through the Gadsden Purchase (1854), in which the United States secured additional territory in present-day southern Arizona and New Mexico

Territorial expansion significance

• Represented a pivotal moment in the realization of the United States' concept of "Manifest Destiny," the belief that the nation's expansion across the North American continent was both justified and inevitable
• Provided the United States with vast new territories in the West, including California, opening up significant opportunities for settlement, trade, and the exploitation of natural resources
• Coincided with the discovery of gold in California (1848), which triggered the California Gold Rush, drawing thousands of settlers and accelerating westward expansion
• Set the stage for increased tensions and conflicts over the extension of slavery into the newly acquired territories, contributing to the growing sectional divide that ultimately led to the American Civil War (1861-1865)

Implications for Mexican citizens

• Presented Mexican citizens in the ceded territories with the choice to either become U.S. citizens or relocate to Mexico
• Despite the treaty's provisions, many Mexicans who chose to stay faced significant discrimination, land dispossession, and marginalization within the United States
• Encountered challenges in integration due to language barriers and cultural differences between Mexican and American societies
• Frequently involved in legal disputes and conflicts over land grants and property rights, as the transition to U.S. governance created uncertainties and opportunities for exploitation
• Experienced segregation and discrimination in various aspects of life, including education, housing, and access to public facilities
• Demonstrated that the treaty's promise of equal rights and citizenship for Mexican Americans was not fully realized in practice, leading to ongoing struggles for civil rights, equality, and recognition