Tucson (possibly from Piman styuk-son, " dark or brown spring," pronounced Tooson), a city and the county-seat of Pima county, Arizona, U.S.A., on the Santa Cruz ', river, in the S.E. part of the state, about, 130 m. S.E. of Phoenix. Pop. (1880), 7007; (1890), 5150; (190o), 7531 (2352 foreign-born, chiefly from Mexico); (1910), 13,193.13,193. It is served by the Southern Pacific and the Twin Buttes railways, the latter connecting with the mines of the Twin Buttes district, about 27 m. south by east, and with the Randolph lines in Mexico. The city lies about 2360 ft. above the sea in a broad valley sheltered by mountains5000-9000ft. high. Its climate, characteristic of southern Arizona, attracts many invalids and winter visitors. Tucson is the seat of the university of Arizona (1891; non-sectarian, coeducational), which is organized under the Morrill Acts; in 1909 it had 40 instructors and 201 students. At Tucson also are a desert botanical laboratory (owning a tract of some 1000 acres about i m. west of the city) established by the Carnegie Institution of Washington, St Joseph's Academy (Roman Catholic); a Roman Catholic cathedral; the Tucson Mission (Presbyterian), a boarding school for Indians, the San Xavier Mission for Indians (Roman Catholic) and a Carnegie library. In 1900 Tucson became the see of a Roman Catholic bishop. The surrounding country is arid and unproductive except where irrigated; but the soil is very rich, and Tucson is the centre of one of the oldest farming and ranching districts of the state. The Southern Pacific railway has division headquarters and repair shops here.
Tucson is first heard of in history in 1699, conjecturally, as an Indian rancheria or settlement; and in 1763 certainly as a visita, in that year temporarily abandoned, of the Jesuit mission of San Xavier del Bac, founded between 1720 and 1732, 9 m. south of what is now Tucson; in 1776 it was made a presidio (San Augustin del Tugison), or military outpost, and although a few Spaniards may possibly have lived there before, the foundation of Tucson as a Spanish town dates from this time. It was never after abandoned during the Indian wars. In 1848 it had 760 inhabitants. The abandonment by the Mexicans in 1848 of the mission towns of Tamacacori (a visita of Guevavi, a mission founded in the first third of the 18th century) and the presidio at Tubac (established before 1752) increased its importance. Tucson lay within the territory acquired by the United States by the Gadsden Purchase in 1853; it was occupied by the United States in 1856. Fort Lowell, 7 m. north-east of the city, was built as a protection against the Apache Indians in 1873; it was abandoned in 1891. In the earlier days of Territorial history Tucson was the political centre of Arizona. Here were held in August 1856 a convention that demanded a Territorial government from Congress, another in April 1860 that organized a provisional government independently of Congressional permission, and others in 1861 that attempted to cast in the lot of Arizona with the Confederate states. Tucson was occupied by the Confederates in February 1862 and by the Union forces in May. It was the Territorial capital from 1867 to 1877. Its prosperity fluctuated with the fortunes of the surrounding mining country. Tucson was incorporated as a town in 1877, and chartered as a city in 1883.
