Book excerpt: In the early 1830s, after decades of relative peace, northern Mexicans and the Indians whom they called "the barbarians" descended into a terrifying cycle of violence. For the next fifteen years, owing in part to changes unleashed by American expansion, Indian warriors launched devastating attacks across ten Mexican states. Raids and counter-raids claimed thousands of lives, ruined much of northern Mexico's economy, depopulated its countryside, and left man-made "deserts" in place of thriving settlements. Just as important, this vast interethnic war informed and emboldened U.S. arguments in favor of seizing Mexican territory while leaving northern Mexicans too divided, exhausted, and distracted to resist the American invasion and subsequent occupation. Exploring Mexican, American, and Indian sources ranging from diplomatic correspondence and congressional debates to captivity narratives and plains Indians' pictorial calendars, "War of a Thousand Deserts" recovers the surprising and previously unrecognized ways in which economic, cultural, and political developments within native communities affected nineteenth-century nation-states. In the process this ambitious book offers a rich and often harrowing new narrative of the era when the United States seized half of Mexico's national territory.