California's involvement in the American Civil War included sending gold east, recruiting volunteer combat units to replace regular forces in territories of the Western United States, maintaining and building numerous camps and fortifications, suppressing secessionist activity (many of these secessionists went east to fight for the Confederacy) and securing the New Mexico Territory against the Confederacy. The State of California did not send its units east, but many citizens traveled east and joined the Union Army and there, some of whom became famous. California's Volunteers also conducted many operations against the native peoples within the state and in the other Western territories of the Departments of the Pacific and New Mexico.