<P> Major issues in recent years include illegal immigration and a crashing of real estate values caused by the Recession of 2008 . </P> <P> Arizona was a part of northern Mexico in the 1840s; it was remote and poor and seldom had outside contacts . The Mexican population, based in Tucson, was a few hundred, in addition to a presidio garrison of about 100 soldiers . The mission was deactivated in 1828 . South of the Gila River it was mostly in the province of Sonora, and a fragment of Chihuahua in the east . To the north Arizona was nominally part of Alta California and a fragment of Santa Fe de Nuevo México in the east . Together with help from Pima and Papago militia the garrison providing a little protection from a hostile Apache population to the east of the San Pedro River and north of the Gila . In the Mexican--American War, the garrison commander avoided conflict with Lieutenant Colonel Cooke and the Mormon Battalion, withdrawing from the town while the Americans marched through the town on their way to California . In the Treaty of Guadalupe Hidalgo (1848), Mexico ceded to the U.S. the northern 70% of modern - day Arizona above the Sonora border along the Gila River . During the California Gold Rush upwards of 50,000 men traveled through on the Southern Emigrant Trail pioneered by Cooke, to reach the gold fields in 1849 . The Pima Villages often sold fresh food and provided relief to distressed travelers among this throng and to others in subsequent years . </P> <P> Starting in 1853, the entirety of present - day Arizona was part of the New Mexico Territory . In 1849, the California Gold Rush led as many as 50,000 miners to travel across the region, leading to a boom in Arizona's population . In 1850, Arizona and New Mexico formed the New Mexico Territory . In 1853, President Franklin Pierce sent James Gadsden to Mexico City to negotiate with Santa Anna, and the United States bought the remaining southern strip area of Arizona and New Mexico in the Gadsden Purchase . </P> <P> Before 1846 the Apache raiders expelled most Mexican ranchers . One result was that large herds of wild cattle roamed southeastern Arizona, By 1850, the herds were gone, killed by Apaches, American sportsmen, contract hunting for the towns of Fronteras and Santa Cruz, and roundups to sell to hungry Mexican War soldiers . and forty - niners en route to California . </P>

Who were some of the first inhabitants do develop thriving cultures in arizona