Tucson is the seat of Pima County, Arizona located 118 miles southeast of Phoenix and 60 miles north of the Mexican border. In 2005, Tucson ranked as the 32nd-largest city and 52nd-largest metropolitan area in the U.S. It is the largest city in southern Arizona and the second largest in the state after Phoenix.

Tucson was probably first visited by Paleo-Indians, known to have been in southern Arizona by about 12,000 years ago. Recent archaeological excavations near the Santa Cruz River have located a village site dating from 4,000 years ago. These people constructed irrigation canals and grew corn, beans, and other crops while gathering wild plants and hunting animals. By 1900, 7,531 people lived in the city. At about this time, the US Veterans Administration had begun construction on the present Veterans Hospital. During the territorial and early statehood periods, Tucson was Arizona's largest city and commercial area, whereas Phoenix was the seat of state government and agriculture. The establishment of Tucson Municipal Airport, the first in the world, increased its prominence. By the 1920s-30s, Phoenix outgrew Tucson and has continued to expand. Tucson has been growing but at a slower pace.