by Carson Love | Dec 5, 2020
The history of Arizona encompasses Spanish, Mexican, and American periods. 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 above the Gila River after the Mexican War, which became part of the Territory of New Mexico. By means of the Gadsden Purchase, the United States secured the northern part of the state of Sonora, which is now Arizona south of the Gila River in 1854.
In 1863, Arizona was split off from the Territory of New Mexico to form the Arizona Territory. The remoteness of the region was eased by the arrival of railroads in 1880. Arizona became a state in 1912 but was primarily rural with an economy based on cattle, cotton, citrus, and copper. Dramatic growth came after 1945, as retirees who appreciated the warm weather and low costs emigrated from the northeast.