Given command of the Army of the West in May 1846 at the beginning of the Mexican War, Stephen Watts Kearny entered New Mexico without resistance and organized a civil government there. He then moved west to California, guided by Kit Carson. Kearny was wounded at the Battle of San Pascual near San Diego in January 1847. Prior to this, Kearny distinguished himself in the War of 1812. He then was assigned to a series of assignments on the frontier, including service in the Yellowstone expedition in 1825.