Treaty of Cahuenga cedes all of California to the United States. Sutter sends relief expeditions to the Donner Party and lets the survivors stay at the fort. Sutter regains control of the fort. 12,000 American troops capture Vera Cruz, Mexico. Mail service is begun between San Francisco and San Diego by two soldiers on horseback.
American troops capture Mexico City.
James Wilson Marshall and Peter L. Wimmer discover gold at the new Sutter's Mill on the American River. Treaty of Guadalupe Hidalgo formally ends the Mexican War, and California is seceded to the United States. All persons then living in Alta California are granted U.S. citizenship. Claims are also ceded to lands in Texas, Colorado, Arizona, New Mexico, Nevada, Utah and part of Colorado. The news is not widely believed in San Francisco.