San Diego is a county in the southern part of California, the United States of America, on the Pacific coast. The county center and largest city in the county is San Diego.
More than 10 thousand years ago and before the arrival of Europeans, the territory of the modern district of San Diego was inhabited by indigenous peoples - Kumeyaay Indians (Kumeyaay, Tipai-Ipai, Kamia, Diegueño), Luiseño (Payomkowishum), Kupeño (Eng. Cupeño, Kuupangaxwichem) and cowilla.
With the advent of European settlers in the 18th century, in 1769 the Franciscan monk Junipero Serra in San Diego founded a Catholic mission (Mission Basilica San Diego de Alcalá). The area became part of New Spain, and from 1804, as a result of the division of California, was part of Upper California until the Mexican Revolution. From 1821 to 1848, San Diego was ruled by Mexico.
Following the results of the Mexican-American War, according to the Guadalupe-Hidalgo Treaty, the district became part of the United States of America in 1848.