1850’s: Americanization of the Valley Occurs

• Towns of Pacheco and Clayton are founded. Intra-valley traffic traverses Rancho Monte del Diablo.
• Galindo home (1856) and Fernando Pacheco adobe (1851) built.
• Soft Coal mines established in northeast Diablo foothills.
• Lime deposits discovered on/near southeast boundary of Rancho Monte del Diablo. Become first commercially exploitable lime to be quarried in California.
• U.S. Land Commissions revalidate Salvio Pacheco’s ownership of Rancho Monte del Diablo.

1860’s: Todos Santos Town Established

• Floods and fires ravage town of Pacheco.
• Early “American” pioneers settle on land around rancho. Some purchase land from Salvio Pacheco.
• Pachecos and Galindo layout town of “Todos Santos” diagonally across Pacheco – Clayton Road near Salvio Pacheco Adobe (1868). They record it officially with Contra Costa County (1869).
• Name “Concord” is used immediately by new settlers to re-identify town of Todos Santos.