On September 23, 1846 General Kearny ordered Col. Alexander W. Doniphan, commander of the 1st regiment of Missouri Mounted Volunteers, to lead an expedition to Chihuahua in support of General Wool. During the 3000-mile march the regiment defeated the Mexicans at the Battle of El Brazito, occupied El Paso, and defeated a Mexican Force at the Battle of Sacramento before marching into Chihuahua on March 1, 1847.
From the description of A. J. Mills Mexican War letter, 1847 (California State Library). WorldCat record id: 742640327