December, 1846 - February, 1847
From June 1846 to June 1847 Colonel Alexander W. Doniphan led his regiment of Missouri volunteers on a 5,500-mile trek from Fort Leavenworth, Kansas to Santa Fe, New Mexico, then south to El Paso and Chihuahua, and eventually to Matamoros, before returning to Missouri.
A well-known Missouri lawyer, Doniphan was elected colonel by the recruits of the 1st Regiment of Missouri Mounted Volunteers in 1846. Doniphan's regiment of one thousand men received only a few days of rudimentary training at Fort Leavenworth, Kansas, before embarking with Stephen W. Kearny for Santa Fe in June, 1846. Kearny's Army of the West captured the town without a battle on August 18. Kearny departed a month later for California, leaving Doniphan in command of the territory. Doniphan sought to deal with the Indian depredations that had ravaged many Mexican frontier communities as he waited for reinforcements from Fort Leavenworth, at which time he was to march south to Chihuahua by way of El Paso. Initially, Doniphan was to coordinate the Chihuahua campaign with General John Wool, whose much larger force was mustered in San Antonio. Logistical challenges plagued Wool's advance, however, and by year's end Zachary Taylor ordered Wool to join his Army of Occupation in northeastern Mexico, where it would meet Santa Anna's main army at Buena Vista in February the following year.
On December 14, 1846, Doniphan marched his regiment of 800 men south toward El Paso del Norte, a 250-mile trek of arid and barren terrain. On Christmas Day, 1846, about ten miles south of Las Cruces, Doniphan's force encountered a Mexican army sent to block its advance to El Paso. U.S. troops dispersed Mexican forces at the Battle of El Brazito, and entered El Paso two days later. The First Missouri regiment spent the following month in El Paso as it waited for supplies and light artillery before beginning its march south into the Mexican interior.
In early February, Doniphan's Missouri Volunteers began their march toward Chihuahua, the most important city in northwest Mexico. En route Doniphan encountered a Mexican army at the Sacramento River, about fifteen miles north of the city. Although facing a force twice its size, the regiment drove the Mexican defenders from their positions on February 8 in a battle that lasted only an hour, suffering minimal casualties. Unable to hold the city, the Mexican army evacuated Chihuahua, which would remain under U.S. occupation for the duration of the war.
Although U.S. forces conducted several long marches during the course of the war, Doniphan's March received considerable attention in the American press, inviting comparisons between Doniphan and Xenophon, the Athenian officer who led Greek soldiers on a thousand-mile march across Asia Minor during the Persian Wars. Dubbed "the American Xenophon," Doniphan and the Missouri Volunteers returned home to a heroes' welcome.