Tucson was originally inhabited around 7000 BC by early Paleo-Indians, and later replaced by groups designated by archaeologists as the Hohokam. As such, Tucson is at the longest continuously inhabited location in the United States. Jesuit missionary Eusebio Francisco Kino visited the area in 1692, and founded the Mission San Xavier del Bac in 1700. The Spanish established a presidio (fort) in 1776 and the town came to be called "Tucson" . Tucson became a part of Mexico after Mexico gained independence from Spain in 1821. The University of Arizona, located in Tucson, was founded in 1885.