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.
Military history of Mexico
The dominant figure of the second quarter of 19th century Mexico was the dictator Antonio López de Santa Anna. During this period, many of the territories in the north were lost to the United States. Santa Anna was the nation's leader during the conflict with Texas, which declared itself independent in 1836, and during the Mexican–American War (1846–48). One of the memorable battles of the U.S. invasion of 1847 was when a group of young Military College cadets (now considered national heroes) fought to the death against a large army of experienced soldiers in the Battle of Chapultepec (September 13, 1847). Ever since this war many Mexicans have resented the loss of much territory, some by means of coercion, and more territory sold cheaply by the dictator Santa Anna (allegedly) for personal profit.