linguistic:translation
Mexican Army

The Mexican Army was a weak and divided force. Only 7 of the 19 states that formed the Mexican federation sent soldiers, armament, and money for the war effort. Many leaders expressed their concern for the country, including Santa Anna who stated that, "The leaders of the army did their best to train the rough men who volunteered, but they could do little to inspire them with patriotism for the glorious country they were honored to serve." According to the leading Mexican conservative politician, Lucas Alamán, the "money spent on arming Mexican troops merely enabled them to fight each other and 'give the illusion' that the country possessed an army for its defense." However, an officer criticized Santa Anna's training of troops, "The cavalry was drilled only in regiments. The artillery hardly ever maneuvered and never fired a blank shot. The general in command was never present on the field of maneuvers, so that he was unable to appreciate the respective qualities of the various bodies under his command... If any meetings of the principal commanding officers were held to discuss the operations of the campaign, it was not known, nor was it known whether any plan of campaign had been formed."

At the beginning of the war, Mexican forces were divided between the permanent forces (permanentes) and the active militiamen (activos). The permanent forces consisted of 12 regiments of infantry (of two battalions each), three brigades of artillery, eight regiments of cavalry, one separate squadron and a brigade of dragoons. The militia amounted to nine infantry and six cavalry regiments. In the northern territories, presidial companies (presidiales) protected the scattered settlements.

Indigenous populations in Mexico played a crucial role in the defending their land. By the beginning of the war, indigenous populations were depleted of their natural resources due to an influx of American settlers. As a result, indigenous populations from the Great Plains region had to rely on raiding American camps in order to survive. Although raiding was much more lucrative than hunting, indigenous population did not have much of a choice. Indigenous soldiers who volunteered to fight with the Mexican Army were often abandoned and compensated unfairly. By raiding, indigenous populations were also able to acquire horses and properly tame them to move efficiently during battles. Captive-taking methods, especially that of the Comanche tribe, were also used to the advantage of the Mexican Army as captives would end up assisting indigenous populations in the raids of American forces.

The Mexican army was using surplus British muskets (such as the Brown Bess), left over from the Napoleonic Wars. While at the beginning of the war most American soldiers were still equipped with the very similar Springfield 1816 flintlock muskets, more reliable caplock models became increasingly popular as the conflict progressed. Some U.S. troops carried more modern weapons that gave them a significant advantage over their Mexican counterparts, such as the Springfield 1841 rifle of the Mississippi Rifles and the Colt Paterson revolver of the Texas Rangers. In the later stages of the war, the U.S. Mounted Rifles were issued Colt Walker revolvers, of which the U.S. Army had ordered 1,000 in 1846. Most significantly, throughout the war, the superiority of the U.S. artillery often carried the day.

In his 1885 memoirs, former U.S. President Ulysses Grant, a veteran of the Mexican war, attributed Mexico's defeat to the poor quality of their army, writing:

"The Mexican army of that day was hardly an organization. The private soldier was picked from the lower class of the inhabitants when wanted; his consent was not asked; he was poorly clothed, worse fed, and seldom paid. He was turned adrift when no longer wanted. The officers of the lower grades were but little superior to the men. With all this I have seen as brave stands made by some of these men as I have ever seen made by soldiers. Now Mexico has a standing army larger than the United States. They have a military school modeled after West Point. Their officers are educated and, no doubt, very brave. The Mexican war of 1846–48 would be an impossibility in this generation."