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.
History of Monterrey
After the country's independence from the Spanish Crown and the foundation of Mexico in 1821, the governments of Mexico and the United States fought the Mexican-American War, which resulted in the loss of more than half of Mexico's national territory. On 23 September 1846 General William J. Worth besieged the city and a battle between the two countries was fought from Cerro del Obispado to the Villa de Guadalupe, known as the Battle of Monterrey. American troops remained in the Mexican territory until 1848 and the Mexico-American War ended with the treaty of Guadalupe Hidalgo in which the conflicting parties agreed that the United States would acquire the territories of Alta California and New Mexico, and the territory between the Nueces River and the Rio Grande, claimed by the Republic of Texas.