when did california become part of the usa
California The California Republic was short lived;[54] the same year marked the outbreak of the Mexican–American War (1846–48).[55] When Commodore John D. Sloat of the United States Navy sailed into Monterey Bay and began the military occupation of California by the United States, Northern California capitulated in less than a month to the United States forces.[56] After a series of defensive battles in Southern California, the Treaty of Cahuenga was signed by the Californios on January 13, 1847, securing American control in California.[57]