Historian Brian DeLay unearths the forgotten role played by Native Americans in the U.S.–Mexican War.

(Image courtesy of Brian DeLay.)
https://clas.berkeley.edu/publications/us-mexican-war-forgotten-foes
“Consider the U.S.–Mexican War of 1846 to 1848. Historians on both sides of the border have framed the war as a story about states. They’ve crafted narratives of the conflict with virtually no conceptual space for the people who actually controlled most of the territory that the two counties went to war over: the Navajos, Apaches, Comanches, Kiowas and other independent Indian peoples who dominated Mexico’s far north.
These native polities are invisible, or at best trivial, in history books about the U.S.–Mexican War, Manifest Destiny and Mexico’s own early national period.

This fact testifies to a colossal case of historical amnesia because Indian peoples fundamentally reshaped the ground upon which Mexico and the United States would compete in the mid-19th century. In the early 1830s, Comanches, Kiowas, Navajos and several tribes of Apaches abandoned imperfect but workable peace agreements that they had maintained with Spanish-speakers in the North since the late 1700s.
They did so for complex reasons that varied from group to group, but declining Mexican diplomatic and military power and expanding American markets were the backdrop for the region’s overall plunge into violence. Groups of mounted Indian men, often several hundred and sometimes even a thousand strong, stepped up attacks on Mexican settlements.
“This sprawling, brutal conflict — what I call the War of a Thousand Deserts — had profound implications not only for the northern third of Mexico but also for how Mexicans and Americans came to view one another prior to 1846, for how the U.S.–Mexican War would play out on the ground and for the conflict’s astonishing conclusion: Mexico losing more than half its national territory to the United States. This outcome, one that continues to shape the power, prosperity and potential of Mexico and the United States today, is incomprehensible without taking non-state societies and their politics into account.“
THE U.S. – MEXICAN WAR: Forgotten Foes | Center for Latin American Studies (CLAS) – 2010 University of California, Berkeley
by Brian DeLay