Army of the Republic of Mexico

Army of the Republic of Mexico

Present in Bexar, March 6, 1836

UnitStrengthEmployment 3/6ArrivalNotes
Cavalry Regiment Dolores290security2/23veterans of the Zacatecas Campaign
Battalion Permanente Matamoros272assault2/23veterans of the Zacatecas Campaign
Battalion Permanente Jimenez274assault2/23Later used against Fannin
Battalion Activo San Luis452assault2/23veterans of the Zacatecas Campaign, Later used against Fannin
Battalion Permanente Allende300?reserve2/23veterans of the Zacatecas Campaign
Zapadores unit185assault3/3combat engineers, veterans of the Zacatecas Campaign
Battalion Permanente Aldama393reserve3/3--
Battalion Activo Toluca324assault3/3veterans of the Zacatecas Campaign, suffered heavily in the assault
Artillery100?not used2/23+--

Available = about 2500 troops, not counting artillery, headquarters, service personnel, and camp followers.

Assault Force = 1507. Mexican sources place the total at 1,400, probably by leaving out the "ineffectives" of each unit. At least one of the reserve batallions was also committed before the fighting ended.

Following March 6, a further five infantry battalions and two cavalry regiments arrived, totalling about 2400 more.

Source: Material on file at the Daughters of the Republic of Texas library, The Alamo, San Antonio, Texas.


The Mexican Army then consisted of 10 permanent infantry battalions and three cavalry regiments, named after heroes or battles of the Mexican War of Independence 1810-21. Personnel were long-service professionals, volunteers serving for eight years and draftees serving for ten. Part of the army had been used the previous May to supress a republican uprising in the Mexican state of Zacatecas.


Infantry units that appeared in the field were of two types: permanente (regular) and activo (militia), and had eight companies of 80 men each. (On paper that is. As with most armies at the time, they were half-strength by the time they reached the front, thanks to disease, straggling, desertion, and recruiting irregularities.) The companies were:
  • Six line companies, armed with the obsolete (in service since 1722) .75-caliber British "Brown Bess" smoothbore musket, useless beyond about 100 yards.
  • One rifle or skirmisher company armed with the less obsolete British Baker .61-calibre rifle, effective to about 250 yards.
  • One "grenadier" company of picked men to serve as assault troops, reserves, etc., also armed with the Brown Bess, and possibly grenades.
Also on foot would be the zapadores (combat engineers, sappers) and the artillery.

Uniforms included a dark blue tailcoat with red trim, and light blue (gray?) pants.


There were four different organizations in the cavalry: permanente (regular), activo (militia), auxilleries (local auxiliaries) and presidal (garrison troop, dragoons.) The cavalry was variously armed with swords, lances, and short-barreled escopetas (carbines.) Incidentally, cavalry units in all armies were smaller then infantry units, since per-man they took up more road space and more front, consumed far more supplies, and cost the government more money. Therefore, the cavalry regiments were comparable to the infantry battalions.

Comparison of Arms:

Neither side had an automatic advantage. Consider:

Many of the Texans had small-bore hunting rifles generally effective to 400 yards. The rest were armed no better than the Mexicans, with a random assortment of personal arms.The shorter-range Mexican arms (bought as Napoleonic War surplus from the British in about 1827) could be reloaded much faster. (Anyway, how often, at ground level, can you see more than 100 yards in any random direction?)
The Texans had high-quality gunpowder manufactured with scientific methods by a company called DuPont.Mexican powder resembled (perhaps was) homemade flashpowder, but on the other hand they did not depend on imported supplies.
Aside from rifles, the Texans had Bowie knives, dueling pistols, shotguns, and multi-barrel "pepper-box" pistols that were more impressive in theory than in practice.The British/Mexican arms could mount a bayonet, which many at the time still considered (for perfectly good reasons, by the way) the decisive weapon.
Personnel in the Texan forces were militiamen and volunteers governed mostly by whim, barely aware there was supposed to be a chain of command. The Mexican Army was a genuine, functional army, although in this campaign Santa Anna had cut many "frills" (like a medical service) for financial reasons. Its officers were professionals, often European mercenaries. Enlisted men, however, were often peasants roped in by press gangs.
The Texan government was barely functional. Support, logistical or otherwise, was not reliable.The Mexican army was beyond support range of its government. "Camp followers" would have increased the headcount involved in the Mexican Army's presence by about 50 percent.
The Texans had as many as 21 artillery tubes inside the Alamo.The Texans could not possibly have manned them all with a standard crew of six trained men each. Probably they did not even get around to mounting them all. The available Mexican artillery was manned by professionals.
Overhanging every engagement was the threat of Mexican horsemen, a threat the Texans had difficulty answering.

(Keep in mind that the artillery on hand might have outwardly resembled that used in the American Civil War of 1861-65, but was actually of a previous technical generation. Designs appearing after 1850 were lighter and more powerful, being designed on scientific principals.

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