History of Hispanic and Latino Americans in the United States
In 1821, Mexico gained independence from Spain, annexing the southwest of the present United States, including Arizona. As missions began to wither, Mexico began auctioning off more land, causing the Pimería Alta and the Apachería to shrink as territory expanded. In the meantime, American mountain men began to enter the region, looking to trap beavers for their pelts. In 1836, Texas declared independence from Mexico and claimed much of the territory in the northern lands of Mexico. When the United States annexed Texas in 1846 over the strong objections of the Mexican government, U.S. troops moved into disputed territory. The hostilities erupted in the Mexican–American War (1846–1848). The U.S. occupied Mexico City and forced the newly founded Mexican Republic to give up its northern half, including the later Arizona.
Convention of 1833
Mexico won its independence from Spain in 1821. After the new country's monarchy was overthrown, the Constitution of 1824 established a federalist republic composed of multiple states. Sparsely populated provinces were denied independent statehood and instead merged with neighboring areas. Mexican Texas, which marked the country's eastern border with the United States, was combined with Coahuila to form the new state Coahuila y Tejas. To facilitate government of the large area, the state was subdivided into several departments; all of Texas was included in the Department of Béxar.