In 1821, Mexico invited the United States to help settle Texas, an invitation that led to the Battle of the Alamo and ultimately set the stage for 80 more years of bloody conflict. In 1846, escalating tensions led to the two-year Mexican-American war, after which Mexico lost half of its territory and the U.S. gained one-third of what is now theirs. When the U.S. didn’t honor its treaty with Mexico, rancher Juan Cortina, dubbed the Robin Hood of the Rio Grande, led a revolt, though it was ultimately unsuccessful. When American expansion spread to longstanding Mexican-American cities in California, Americans of Mexican heritage turned inward to preserve their culture.