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.
First Mexican Republic
The Spanish overseas possession of the Viceroyalty of New Spain lasted for 300 years, from 1521 with the fall of the Aztec capital of Tenochtitlan and the foundation of Mexico City until the collapse of the viceroyalty in following years of civil war and military stalemate. An insurgency for independence from Spain lasted from the initial 1810 mass revolt, led by secular cleric Miguel Hidalgo and continued under another secular cleric, José María Morelos, and carried on the hot country of Mexico's south by Vicente Guerrero. Augustin Iturbide, a royalist military officer born in New Spain of Spanish parents, made a strategic alliance with Guerrero under the Plan of Iguala, in which the former foes fought in tandem to oust Spanish rule. The plan proclaimed Mexico a nation-state; Roman Catholicism as the sole religion; the equality of Spaniards and American-born Spaniards and abolished legal racial designations, and was to be a constitutional monarchy. On September 27, 1821, Mexico obtained its sovereignty under the Treaty of Córdoba, which recognized New Spain as an independent empire, which took the name the Mexican Empire.