Concord ( KON-kerd) is the largest city in Contra Costa County, California. According to an estimate completed by the United States Census Bureau, the city had a population of 129,295 in 2019 making it the 8th largest city in the San Francisco Bay Area. Founded in 1869 as Todos Santos by Don Salvio Pacheco II, a noted Californio ranchero, the name was later changed to Concord. The city is a major regional suburban East Bay center within the San Francisco Bay Area, and is 29 miles (47 kilometres) east of San Francisco.
The valleys north of Mount Diablo were inhabited by the Miwok people, who hunted elk and fished in the numerous streams flowing from the mountain into the San Francisco Bay. It is important to note Miwok and other indigenous people still live within city limits. In 1772, Spanish explorers began to cross the area, but did not settle there. In 1834, the Mexican land grant Rancho Monte del Diablo at the base of Mount Diablo was granted to Salvio Pacheco (for whom the nearby town of Pacheco is named).
Concord was founded under the name of Todos Santos ("all saints"; a name still borne by the central city plaza and park between Willow Pass Road and Salvio Street), on the initiative of Pacheco in 1869. It achieved prominence in the 19th century when most residents of Pacheco relocating to Concord to avoid the devastation of fire and flood which crippled Pacheco's formerly booming economy.