The Mexican Army in 1846

Topic- Mexican Military Preparation

The Mexican army on the eve of war with the United States reflected the political instability and deep racial divisions that had plagued the nation since independence. In recent years, it had been used primarily in support of the many revolutions that had brought a succession of caudillos to power. The officer class consisted largely of professional soldiers from Europe and Mexico’s political elite. Legal guarantees of immunity from civil prosecution, the fuero militar, hampered civilian control over the military. Operating with virtual autonomy where they were garrisoned, military leaders cultivated close ties with local political leaders, further compromising their loyalty to the national government.

The rank and file was composed of poorly trained and irregularly paid conscripts. Each October, the army held a lottery to fill its ranks. Many professions were exempt from military service, while affluent citizens who were subject to the lottery frequently hired substitutes. As a result, recruits came largely from the lowest socio-economic classes. The few volunteers who joined the army served for eight years; conscripts served for ten. By contrast, enlistees in the U.S. Army served for five years. Soldados received fifteen pesos a month, from which they had to pay for clothing and food. Conscripts were difficult to train, prone to desertion, and lacked discipline and cohesion.

Upon the outbreak of war with the United States in 1846, Mexico had more than 30,000 men under arms: 19,000 in the regular army (permanentes), supplemented by 10,500 in the active militia (activos). Regular army officers commanded the activo units. The activos’ role was to augment the permanentes during times of national emergency, although in reality these troops remained on permanent duty. In addition, individual states had the right to raise their own civic militias (civicos) to deal with bandits and Indian depredations. The civicos, however, like the regular army itself, often served a political function as much as a military one, having frequently been used by the state governors to thwart the power of the central government.

Since independence, the government had struggled to pay its soldiers and to meet even the most basic logistical needs of the army. Additionally, what monies actually were appropriated often ended up in the pockets of senior commanders. In the absence of a procurement system, army commanders routinely imposed forced requisitions on local communities or lived off the land. With logistical support at a minimum, the army depended on female camp followers, the soldadera, to secure clothing and extra rations for the troops. They also prepared meals and cleaned and maintained equipment, both in camp and on the march. Over time, these soldadera came to be considered as much a part of the military establishment as the army itself.

Without an armaments industry of its own, Mexico relied entirely on surplus weaponry imported from Europe. As in all armies of the day, the Mexican infantry’s primary weapon was a smoothbore musket. In the 1830s, Mexico purchased surplus British India Pattern "Brown Bess" muskets. First manufactured in 1797 to meet Great Britain’s needs during the wars with France, these muskets acquired a reputation for unreliability. The "Brown Bess" was a .75 caliber smoothbore musket that used a paper cartridge, weighed just under ten pounds, and carried an eighteen-inch socket bayonet. It had an effective range of up to 100 yards. The Mexican army’s 140 pieces of artillery, also vintage European imports, were in a similarly dilapidated condition, having suffered from years of neglect. Dispersed at garrisons throughout the Mexican republic, many remained inaccessible as a result of poor roads, and would play little part in the coming war with the United States. In addition, gunpowder produced in Mexico contained high levels of sulfur and charcoal, making it inferior to that used by the U.S. Army. As a result, Mexican artillery projectiles often fell short of their intended range.

The light cavalry was generally considered the most effective branch of the Mexican army. Unlike the infantry, the cavalry had proven highly successful during the Texas Revolution, winning victories under General José de Urrea against the colonists at San Patricio, Refugio, and Coleto Creek. The cavalry troopers were equipped with nine-foot lances which were effective weapons when used to pursue a routed enemy. But cavalry units were easily repulsed by disciplined, formed infantry. Moreover, as the opening battles of the war would demonstrate, a lancer charge by the cavalry could easily be broken up by concentrated artillery fire.

Although the Mexican army had often been deployed during times of political upheaval, it had little experience as an instrument of national defense. Dominated by conservative centralists whose power base was confined largely to the Valley of Mexico, it had manifested little interest in protecting the far northern frontier, which had been devastated by years of incessant Comanche raids. The military establishment had enjoyed somewhat more success in the simmering conflict with the Lone Star republic. Headquartered in Matamoros, the 3,000-man Army of the North had mounted two incursions into Texas in 1842, occupying San Antonio on both occasions. The raids had elicited calls for reprisals in Texas, which had dispatched a volunteer army to raid Mexican towns along the Rio Grande. The expedition met with defeat at Ciudad Mier, a town just below the river, during a two-day battle with the Army of the North on December 25-26, 1842. This was the seasoned force that would confront Zachary Taylor’s Army of Occupation during the early months of the war.

On the eve of the war with the United States, the Herrera government’s minister of war. Pedro Garcéa Conde, sought to implement sweeping reforms to revitalize Mexico’s decaying military establishment. The former commander of the Colegio Militar—he had been responsible for moving the academy to its Chapultepec Castle in 1844—Conde had redesigned the school’s curriculum to reflect the technical orientation of the French military education, which emphasized such subjects as mathematics, physics, and engineering. As minister of war, Conde aimed to revamp the army’s command structure, consolidating small, scattered units into larger garrisons and reducing the number of regional commands. The government also instituted a new national guard, unpaid volunteers who were to take the place of the activos, serving only in times of national emergency. The plan ran into stiff resistance from the regular army, which regarded it as an attempt by the Herrera government to usurp its power. Political infighting and resistance from vested interests at both the national and local level hindered the implementation of Conde’s reforms, which were shelved with the collapse of the Herrera government in December 1845, four months before the outbreak of fighting on the Rio Grande.

Don Gross


DePalo, William A. Jr. The Mexican National Army, 1822-1852. College Station, Texas: Texas A&M University Press, 1997.

Lamego, Miguel A. Sanchez. The Second Mexican-Texas War, 1841-1843. Hillsboro, Texas: Hill Junior College, 1972.

National Park Service. Palo Alto Battlefield. A Thunder of Cannon: Archeology of the Mexican-American War Battlefield of Palo Alto.

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