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.
Mexican War of Independence
After 1810 the independence movement went through several stages, as leaders were imprisoned or executed by forces loyal to Spain. At first the rebels disputed the legitimacy of the French-installed Joseph Bonaparte while recognizing the sovereignty of Ferdinand VII over Spain and its colonies, but later the leaders took more radical positions, rejecting the Spanish claim and espousing a new social order including the abolition of slavery. Secular priest José María Morelos called the separatist provinces to form the Congress of Chilpancingo, which gave the insurgency its own legal framework. After the defeat of Morelos, the movement survived as a guerrilla war under the leadership of Vicente Guerrero. By 1820, the few rebel groups survived most notably in the Sierra Madre del Sur and Veracruz.