The Treaty of Guadalupe Hidalgo

In 1848, at the conclusion of the U.S.- Mexican War, the two countries signed the Treaty of Guadalupe-Hidalgo. The treaty called for Mexico to give up almost half of its territory, which included modern-day California, Arizona, New Mexico, Texas and parts of Colorado, Nevada, and Utah. In return, the U.S. paid $15 million in compensation for war-related damage to Mexican land.

Among the notable aspects of the treaty, it set the Texas border at the Rio Grande; it provided for the protection of the property and civil rights of Mexican nationals who would now be living on U.S. soil; the United States agreed to police its side of the border; and both countries agreed to compulsory arbitration of future disputes. However, when the United States Senate ratified the treaty, it erased Article 10, which guaranteed the protection of Mexican land grants; Article 9, which deals with citizenship rights, was also weakened. This in turn created an anti-Mexican atmosphere that spurred the violation of their civil rights. In Texas, Mexicans were restricted from voting. In New Mexico, Mexicans were the victims of violence, while in California, laws against them were passed, some of which were known as the Greaser Laws.


At the time of the treaty, approximately 80,000 Mexicans lived in the ceded territory, which comprised only about 4 percent of Mexico’s population. Only a few people chose to remain Mexican citizens compared to the many that became United States citizens. Most of the 80,000 residents continued to live in the Southwest, believing in the guarantee that their property and civil rights would be protected. Sadly, this would not always be the case. By the end of the 19th century, most Mexicans had lost their land, either through force or fraud.

In the Chicano movement in the late 1960s, New Mexico land rights leader Reies Lopez Tijerina and his Alianza movement cited the Treaty of Guadalupe Hidalgo in their fight to regain American-seized Mexican land. In 1972, the Brown Berets youth organization also cited the treaty in their takeover of Catalina Island.

In terms of property ownership, many property rights existing under Spanish and Mexican land grants were not recognized by the United States. In California, approximately 27 percent of land grant claims were rejected; in the territory of New Mexico, some 76 percent of such claims were rejected.