History of Arizona

The history of Arizona encompasses the Paleo-Indian, Archaic, Post-Archaic, Spanish, Mexican, and American periods. About 10,000 to 12,000 years ago, Paleo-Indians settled in what is now Arizona. A few thousand years ago, the Ancestral Puebloan, the Hohokam, the Mogollon and the Sinagua cultures inhabited the state. However, all of these civilizations mysteriously disappeared from the region in the 15th and 16th centuries. Today, countless ancient ruins can be found in Arizona. Arizona was part of the state of Sonora, Mexico from 1822, but the settled population was small. In 1848, under the terms of the Mexican Cession the United States took possession of Arizona north of the Gila River. It became part of the Territory of New Mexico. In 1854 the United States purchased the part of the Arizona south of the Gila River, which allowed a rail connection from Yuma to El Pase..

In 1863, Arizona was split off from the Territory of New Mexico to form the Arizona Territory. The remoteness of the region ended with the arrival of railroads in 1880. Arizona became a state in 1912. It was primarily rural with an economy based on cattle, cotton, citrus, and copper. Dramatic growth came after 1945, as retirees and young families who appreciated the warm weather and low costs emigrated from the Northeast and Midwest. By the 1990s many new arrivals came from California, where housing was much more expensive.