To get a complete grasp of understanding the Mexican American War in California, it's necessary to stand back and review the state of California in 1846. The military was extremely weak. The Monterey presidio had so little powder for its three cannons, that ships cannot be saluted. The San Francisco presidio was ungarrisoned. Besides that, enough temporary takeovers had already occurred -- Brouchard in 1818, Alvarado in 1836, and Jones in 1842. A good majority of the Californios did not expect to remain within Mexico very much longer. The idea that any military expedition at all could capture California was in the back of the everyone"s minds. .

             The number of Americans in California was small, but growing at a rapidly increasing rate. Americans hold key business and even government positions. The most powerful Californio in the north was Mariano Guadalupe Vallejo, a known American sympathizer. The northeastern frontier is held by Americans at Sutter"s fort. Illegal American trappers roam freely throughout the Sierra Nevadas. Wagon trails have been developed through to Utah and America to the East. The American Pacific Fleet is a considerable force whereas the California fleet consisted of a single unarmed vessel. Pio Pico the newly installed Mexican governor is located at Los Angeles, and has as low an opinion of California defense as anyone. His position is tenuous anyway; as recently as February 20, 1845, Californios under Alvarado again had attacked the previous governor in an unsuccessful revolt. In short, California was a conquest waiting to be conquered, and it seems the Americans were in position to accomplish that mission.

             John C. Fremont, I think envisioned himself as the California conqueror. He was a lieutenant in the Army Corps of Topographical Engineers, and well known in the U.S. for a series of Western explorations, including the accurate mapping of the Oregon Trail. His wife was the daughter of Senator Thomas Benton, and she herself was an accomplished writer who worked to publish Fremont's fame.