Overnight, Mexicans became foreigners in their own land.

When the Treaty of Guadalupe Hidalgo was signed on Feb. 2, 1848, Mexico ceded about half of its territory to the United States, mainly parts of what are now Arizona, California, New Mexico and Texas.

Experts say the treaty that ended the Mexican-American War (1846-1848) also created a new ethnic group - Mexican-American - and started a civil-rights struggle.

While the authors of the accord promised property and citizenship rights for the Mexicans who suddenly found themselves living north of the newly established border, none was granted.

The original document will be displayed in Tucson this month. It is a document that continues to shape people's perceptions of identity, said historian Michael Brescia, associate curator at Arizona State Museum. "The international border exists, in part, because of the treaty," he said.

Key original excerpts from the historic treaty can be seen at the Arizona State Museum starting Wednesday and until Feb. 28. The featured originals on display are on loan from the national archives and brought to Tucson by a local nonprofit, Amistades Inc.

The complete bilingual treaty is housed in the National Archives in Washington, D.C.

"The articles coming to us are the most important excerpts from the larger documents," Brescia said in a press release. "Visitors to this exhibit will see Article V, for example, that established the location of the international border."


The Treaty of Guadalupe Hidalgo was named for the town near Mexico City where it was signed. The peace treaty, historians say, was largely dictated by the U.S. to a military-occupied Mexico and ended the war.

There is the misconception that Mexico sold the territory to the U.S., but the 15 million pesos it received for the land wasn't a payment: "It was in compensation for war-related damage to Mexican property," according to the history book "Historia General de Mexico," published by Colegio de Mexico in 2000.

"It wasn't a payment for the land," the book says. "It had been conquered."


Experts said the treaty benefited the United States because, for a relatively small cost, it acquired land that would help the country push industrial development.

"A very high percentage of the economic growth in the U.S. is based on the production from territories that belonged to Mexico, like California and Texas," said Oscar J. Martínez, regents professor in the history department at the University of Arizona.

He noted that much of U.S. mineral production comes from land obtained through the treaty. "It's a huge loss for Mexico and a huge gain for the United States," he said.

Effects were more than economic. In Texas, for example, Mexicans weren't allowed to vote; in New Mexico, some were targets of violence; and in California laws against Mexicans were passed - some known as the "greaser" laws.


When the U.S. Senate ratified the treaty, it deleted Article X, guaranteeing the protection of Mexican land rights. It also modified Article IX, which guaranteed citizenship rights for Mexicans in the new land.

There were about 80,000 Mexicans living in the ceded territory - about 20 percent of Mexico's population. Most decided to stay and live in the southwestern U.S. By the end of the 19th century, most Mexicans had lost their lands and were forcibly removed.

Mexico had failed to set up a way to enforce the treaty, so there wasn't an international agency to monitor violations of the agreement.

"That would have been helpful," said Richard Griswold del Castillo, a treaty scholar and professor of Mexican-American studies at San Diego State University.

Contact reporter Mariana Alvarado at 573-4597 or malvarado@azstarnet.com


• What: Display of original pages from historic Treaty of Guadalupe Hidalgo.

• When: Feb. 2 through 28, from 10 a.m. to 5 p.m.

• Where: Arizona State Museum, 1013 E. University Blvd. Phone: 621-6302.

• Cost: $5


Tucson, Yuma and Nogales were not included as part of the Arizona territory ceded to the United States in the Treaty of Guadalupe Hidalgo in 1848. Those cities were purchased in 1854 by the U.S. in a treaty signed by James Gadsden, the American ambassador to Mexico at that time. The treaty is known as the Gadsden Purchase, or Venta de La Mesilla.