10 States in The U.S. That Were Once A Part of Mexico

  Our Native American brothers and sisters are the only people who can truly claim the United States was their original land

Photo: Wikimedia/Milenioscuro

Photo: Wikimedia/Milenioscuro

Our Native American brothers and sisters are the only people who can truly claim the United States was their original land. Nonetheless, it’s important to look at what parts of the country were once in Mexican hands because that same land now has states that are very anti-immigration, which is ironic, to say the least. Many ignorant people are telling immigrants, especially Mexicans, to “Go back to their country,” when states like Texas, Arizona, and California were actually once their country. If anything, they’re returning to what was part of their homeland.

In an effort to educate the masses, so that we can better understand history, understand each other, and erase ignorance, we thought it was important to look back and see exactly which states used to be Mexico that the country was forced to concede to the United States. Some of them will definitely shock you!



California was under Mexican rule from 1821, when Mexico gained its independence from Spain, until 1848. That year, the Treaty of Guadalupe Hidalgo was signed (on February 2), giving California over to United States control.




Nevada is another state that was once under Mexican control. Like California, it became part of the U.S. with the signing of the Treaty of Guadalupe Hidalgo. Before then, Nevada was part of Alta California, which included California, Baja California, Utah, about a quarter of Colorado, parts of Arizona, Wyoming and New Mexico.



Arizona came under U.S. control in 1848 and didn’t become a state until 1912. Before 1848, Arizona was part of the Mexican state of Sonora.



When the Mormons settled in the area of today’s Utah in 1847, they claimed it as their own, despite it being a Mexican territory. The state was part of the 1848 Treaty of Guadalupe Hidalgo, which also included California, the majority of Arizona, about half of New Mexico, Colorado, and parts of Wyoming.



Texas was part of Mexico, from 1821 to 1836. The Federal Constitution of the United Mexican States of 1824 had joined Texas with Coahuila and Nuevo Leon into one state. Texas later became the 28th U.S. state on December 29, 1845.



About a quarter of Colorado was part of the Mexican Cession, land that was given to the United States by Mexico in 1848. Colorado is Spanish for red. The name comes from what the Spaniards called the reddish-tinged  Colorado River (Rio Colorado).


New Mexico

New Mexico is another state that was once part of Mexico. In 1848, the United States paid Mexico $15 million for the Mexican Cession land, which included present-day New Mexico.



Part of Wyoming (nearly 10%) was once part of Mexico. Sections of Wyoming were also claimed at one point by Great Britain, France, Spain, and the state of Texas.


Can you believe Kansas was part of Mexico? The southwestern part of the state was under Mexican rule, and later was claimed by the Republic of Texas, until 1848 (although the rest of the state was already under U.S. control in 1803).



Oklahoma, too, was once Mexican territory. Like Kansas, a part of Oklahoma was included in the Louisiana Purchase (1803), while its panhandle was under Mexican rule until the United States received it in 1848.

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latino history Mexican history Mexico states that were Mexico U.S. history United States
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