who led a mission to california in 1846
Californio The only other United States military force in California at the time was a small exploratory expedition led by Lieutenant Colonel John C. Frémont, made up of 30 topographical, surveying, etc. army troops and about 25 men hired as guides and hunters. The Frémont expedition had been dispatched to California, in 1845, from the United States Army Corps of Topographical Engineers.