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Armed conflict between the US and Mexico (1846–1848) From Wikipedia, the free encyclopedia
The Mexican–American War,[a] also known in the United States as the Mexican War, and in Mexico as the United States intervention in Mexico,[b] was an invasion of Mexico by the United States Army from 1846 to 1848. It followed the 1845 American annexation of Texas, which Mexico still considered its territory because it refused to recognize the Treaties of Velasco, signed by President Antonio López de Santa Anna after he was captured by the Texian Army during the 1836 Texas Revolution. The Republic of Texas was de facto an independent country, but most of its Anglo-American citizens who had moved from the United States to Texas after 1822 wanted to be annexed by the United States.[5][6]
Mexican–American War | |||||||||
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Clockwise from top: Winfield Scott entering Plaza de la Constitución after the Fall of Mexico City, U.S. soldiers engaging the retreating Mexican force during the Battle of Resaca de la Palma, U.S. victory at Churubusco outside of Mexico City, Marines storming Chapultepec castle under a large U.S. flag, Battle of Cerro Gordo | |||||||||
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Belligerents | |||||||||
United States | Mexico | ||||||||
Commanders and leaders | |||||||||
Strength | |||||||||
73,532[2] | 82,000[2] | ||||||||
Casualties and losses | |||||||||
Total: 18,130 |
Total: 35,000
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Including civilians killed by violence, military deaths from disease and accidental deaths, the Mexican death toll may have reached 25,000[2] and the American death toll reached 13,283.[4] |
Sectional politics over slavery in the United States had previously prevented annexation because Texas would have been admitted as a slave state, upsetting the balance of power between Northern free states and Southern slave states.[7] In the 1844 United States presidential election, Democrat James K. Polk was elected on a platform of expanding U.S. territory to Oregon, California (also a Mexican territory), and Texas by any means, with the 1845 annexation of Texas furthering that goal.[8] However, the boundary between Texas and Mexico was disputed, with the Republic of Texas and the U.S. asserting it to be the Rio Grande and Mexico claiming it to be the more-northern Nueces River. Polk sent a diplomatic mission to Mexico in an attempt to buy the disputed territory, together with California and everything in between for $25 million (equivalent to $778 million in 2023), an offer the Mexican government refused.[9][10] Polk then sent a group of 80 soldiers across the disputed territory to the Rio Grande, ignoring Mexican demands to withdraw.[11][12] Mexican forces interpreted this as an attack and repelled the U.S. forces on April 25, 1846,[13] a move which Polk used to convince the Congress of the United States to declare war.[11]
Beyond the disputed area of Texas, U.S. forces quickly occupied the regional capital of Santa Fe de Nuevo México along the upper Rio Grande. U.S. forces also moved against the province of Alta California and then turned south. The Pacific Squadron of the U.S. Navy blockaded the Pacific coast in the lower Baja California Territory. The U.S. Army, under Major General Winfield Scott, invaded the Mexican heartland via an amphibious landing at the port of Veracruz on March 9 and captured the capital, Mexico City, in September 1847. Although Mexico was defeated on the battlefield, negotiating peace was a politically fraught issue. Some Mexican factions refused to consider any recognition of its loss of territory. Although Polk formally relieved his peace envoy, Nicholas Trist, of his post as negotiator, Trist ignored the order and successfully concluded the 1848 Treaty of Guadalupe Hidalgo. It ended the war, and Mexico recognized the cession of present-day Texas, California, Nevada, and Utah as well as parts of present-day Arizona, Colorado, New Mexico, and Wyoming. The U.S. agreed to pay $15 million for the physical damage of the war and assumed $3.25 million of debt already owed by the Mexican government to U.S. citizens. Mexico relinquished its claims on Texas and accepted the Rio Grande as its northern border with the United States.
The victory and territorial expansion Polk envisioned inspired patriotism among some sections of the United States, but the war and treaty drew fierce criticism for the casualties, monetary cost, and heavy-handedness. The question of how to treat the new acquisitions intensified the debate over slavery in the United States. Although the Wilmot Proviso that explicitly forbade the extension of slavery into conquered Mexican territory was not adopted by Congress, debates about it heightened sectional tensions. Some scholars see the Mexican–American War as leading to the American Civil War. Many officers who had trained at West Point gained experience in the war and later played prominent leadership roles during the Civil War. In Mexico, the war worsened domestic political turmoil and led to a loss of national prestige, as it suffered large losses of life in both its military and civilian population, had its financial foundations undermined, and lost more than half of its territory.
Mexico obtained independence from the Spanish Empire with the Treaty of Córdoba in 1821 after a decade of conflict between the royal army and insurgents for independence, with no foreign intervention. The conflict ruined the silver-mining districts of Zacatecas and Guanajuato. Mexico began as a sovereign nation with its future financial stability from its main export destroyed. Mexico briefly experimented with monarchy, but became a republic in 1824. This government was characterized by instability,[14] and it was ill-prepared for a major international conflict when war broke out with the U.S. in 1846. Mexico had successfully resisted Spanish attempts to reconquer its former colony[15] in the 1820s and resisted the French in the so-called Pastry War of 1838[16] but the secessionists' success in Texas and the Yucatán against the centralist government of Mexico showed its political weakness as the government changed hands multiple times.[17] The Mexican military and the Catholic Church in Mexico, both privileged institutions with conservative political views, were stronger politically than the Mexican state.[citation needed]
The United States' 1803 Louisiana Purchase resulted in an undefined border between Spanish colonial territories and the U.S. Some of the boundary issues between the U.S. and Spain were resolved with the Adams-Onís Treaty of 1818. U.S. negotiator John Quincy Adams wanted clear possession of East Florida and establishment of U.S. claims above the 42nd parallel, while Spain sought to limit U.S. expansion into what is now the American Southwest. The U.S. sought to purchase territory from Mexico, starting in 1825, in order to settle some of these issues. U.S. President Andrew Jackson made a sustained effort to acquire northern Mexican territory, with no success.[18]
Historian Peter Guardino states that in the war "the greatest advantage the United States had was its prosperity."[19] With the Industrial Revolution across the Atlantic increasing the demand for cotton for textile factories, there was a large external market for cotton produced by enslaved African-American labor in the southern states. This demand helped fuel expansion into northern Mexico. Although there were political conflicts in the U.S., they were largely contained by the framework of the constitution and did not result in revolution or rebellion by 1846, but rather by sectional political conflicts. Northerners in the U.S. sought to develop the country's existing resources and expand the industrial sector without expanding the nation's territory. The existing balance of sectional interests would be disrupted by the expansion of slavery into new territory. The Democratic Party, to which President Polk belonged, in particular strongly supported expansion.[20]
Neither colonial Mexico nor the newly sovereign Mexican state effectively controlled Mexico's far north and west.[citation needed] Mexico's military and diplomatic capabilities declined after it attained independence from Spain in 1821 and left the northern half of the country vulnerable to attacks by Comanche, Apache, and Navajo Native Americans.[21] The Comanche, in particular, took advantage of the weakness of the Mexican state to undertake large-scale raids hundreds of miles into the country to acquire livestock for their own use and to supply an expanding market in Texas and the U.S.[22]
The northern area of Mexico was sparsely settled because of its challenging climate and topography.[23] Mostly high desert with scarce rainfall, it supported little sedentary agriculture during the pre-Hispanic and colonial periods.[24] After independence, Mexico became preoccupied with internal struggles that sometimes verged on civil war, and the worsening situation on the northern frontier was largely neglected.[citation needed] In northern Mexico, the end of Spanish rule was marked by the end of financing for garrisoned presidios and the pay-offs to Native Americans to maintain peace. In the absence of effective governance, Comanche and Apache took to raiding for livestock and looted much of the northern countryside outside of the scattered towns. The raids after 1821 resulted in many deaths, halted most transportation and communications, and decimated the ranching industry that was a mainstay of the northern economy. As a result, the demoralized civilian population of northern Mexico put up little resistance to the invading U.S. army.[25]
Furthermore, distance and hostile activity by Native Americans made communications and trade between the heartland of Mexico and provinces such as Alta California and New Mexico increasingly difficult. As a result, at the outbreak of the war, New Mexico was economically dependent on trade with the United States via the eastern branch of the Santa Fe Trail.[26]
The Mexican government's policy of allowing the settlement of U.S. citizens in its province of Tejas was aimed at expanding control into Comanche lands, the Comancheria. However, rather than settling in the dangerous central and western parts of the province, Anglos preferred to settle in East Texas with its rich farmland contiguous with the southern U.S. slave states. As settlers poured in from the U.S., the Mexican government discouraged further migration with its 1829 abolition of slavery.[27]
During the Spanish colonial era, the Californias (i.e., the Baja California peninsula and Alta California) were sparsely settled. After Mexico became independent, it shut down the missions and reduced its military presence. In 1842, the U.S. minister in Mexico, Waddy Thompson Jr., suggested Mexico might be willing to cede Alta California to the U.S. to settle debts, saying: "As to Texas, I regard it as of very little value compared with California, the richest, the most beautiful, and the healthiest country in the world ... with the acquisition of Upper California we should have the same ascendency on the Pacific ... France and England both have had their eyes upon it."[28]
U.S. President John Tyler's administration suggested a tripartite pact to settle the Oregon boundary dispute and provide for the cession of the port of San Francisco from Mexico. Lord Aberdeen declined to participate but said Britain had no objection to U.S. territorial acquisition there.[29] The British minister in Mexico, Richard Pakenham, wrote in 1841 to Lord Palmerston urging "to establish an English population in the magnificent Territory of Upper California", saying that "no part of the World offering greater natural advantages for the establishment of an English colony ... by all means desirable ... that California, once ceasing to belong to Mexico, should not fall into the hands of any power but England ... there is some reason to believe that daring and adventurous speculators in the United States have already turned their thoughts in this direction." By the time the letter reached London, though, Sir Robert Peel's Tory government, with its Little England policy, had come to power and rejected the proposal as expensive and a potential source of conflict.[30][31]
Pío Pico, the last governor of Alta California, advocated that California achieve independence from Mexico and become a British protectorate.[32][33]
In 1842, Mexico forcibly replaced California Governor Juan Bautista Alvarado with Manuel Micheltorena. Micheltorena was sent up from lower Mexico, along with an army, that had largely been recruited from Mexico's worst jails. The Californios resented this, partly because California had previously been governed by native-born Californios, partly because Micheltorena's policies were unpopular, and also because the soldiers in Micheltorena's army got a reputation for spending much of their time stealing the local Californios' chickens. Women were not considered safe from the depredations of Micheltorena's army.[32][34][35][36]
Former Governor Alvarado organized a revolt in 1845, which culminated in the Battle of Providencia in Cahuenga Pass near Los Angeles. As a result of the actions of pioneer California rancher John Marsh, Micheltorena's forces were defeated.[32][34][35][36]
In 1800, Spain's colonial province of Texas (Tejas) had few inhabitants, with only about 7,000 non-native settlers.[37] The Spanish crown developed a policy of colonization to more effectively control the territory. After independence, the Mexican government implemented the policy, granting Moses Austin, a banker from Missouri, a large tract of land in Texas. Austin died before he could bring his plan of recruiting American settlers for the land to fruition, but his son, Stephen F. Austin, brought over 300 American families into Texas.[38] This started the steady trend of migration from the United States into the Texas frontier. Austin's colony was the most successful of several colonies authorized by the Mexican government. The Mexican government intended the new settlers to act as a buffer between the Tejano residents and the Comanches, but the non-Hispanic colonists tended to settle in areas with decent farmland and trade connections with Louisiana rather than farther west where they would have been an effective buffer against the Natives.
In 1829, because of the large influx of American immigrants, the non-Hispanic outnumbered native Spanish speakers in Texas. President Vicente Guerrero, a hero of Mexican independence, moved to gain more control over Texas and its influx of non-Hispanic colonists from the southern U.S. and discourage further immigration by abolishing slavery in Mexico.[37][39] The Mexican government also decided to reinstate the property tax and increase tariffs on shipped American goods. The settlers and many Mexican businessmen in the region rejected the demands, which led to Mexico closing Texas to additional immigration, which continued from the United States into Texas illegally.
In 1834, Mexican conservatives seized the political initiative, and General Antonio López de Santa Anna became the centralist president of Mexico. The conservative-dominated Congress abandoned the federal system, replacing it with a unitary central government that removed power from the states. Leaving politics to those in Mexico City, General Santa Anna led the Mexican army to quash the semi-independence of Texas. He had done that in Coahuila (in 1824, Mexico had merged Texas and Coahuila into the enormous state of Coahuila y Tejas). Austin called Texians to arms and they declared independence from Mexico in 1836. After Santa Anna defeated the Texians in the Battle of the Alamo, he was defeated by the Texian Army commanded by General Sam Houston and was captured at the Battle of San Jacinto. In exchange for his life Santa Anna signed a treaty with Texas President David Burnet ending the war and recognizing Texian independence. The treaty was not ratified by the Mexican Congress as it had been signed by a captive under duress.[40] Although Mexico refused to recognize Texian independence, Texas consolidated its status as an independent republic and received official recognition from Britain, France, and the United States, which all advised Mexico not to try to reconquer the new nation. Most Texians wanted to join the United States, but the annexation of Texas was contentious in the U.S. Congress, where Whigs and Abolitionists were largely opposed.[41]: 150–155 In 1845, Texas agreed to the offer of annexation by the U.S. Congress and became the 28th state on December 29, 1845, which set the stage for the conflict with Mexico.[42]
By the Treaties of Velasco made after Texans captured General Santa Ana after the Battle of San Jacinto, the southern border of Texas was placed at the "Rio Grande del Norte." The Texans claimed this placed the southern border at the modern Rio Grande. The Mexican government disputed this placement on two grounds: first, it rejected the idea of Texas independence; and second, it claimed that the Rio Grande in the treaty was actually the Nueces River, since the current Rio Grande has always been called "Rio Bravo" in Mexico. The latter claim belied the full name of the river in Mexico, however: "Rio Bravo del Norte." The ill-fated Texan Santa Fe Expedition of 1841 attempted to realize the claim to New Mexican territory east of the Rio Grande, but its members were captured by the Mexican Army and imprisoned. Reference to the Rio Grande boundary of Texas was omitted from the U.S. Congress's annexation resolution to help secure passage after the annexation treaty failed in the Senate. President Polk claimed the Rio Grande boundary, and when Mexico sent forces over the Rio Grande, this provoked a dispute.[43]
In July 1845, Polk sent General Zachary Taylor to Texas, and by October, Taylor commanded 3,500 Americans on the Nueces River, ready to take by force the disputed land. At the same time, President Polk wrote to the American consul in the Mexican territory of Alta California, disclaiming American ambitions in California but offering to support independence from Mexico or voluntary accession to the United States, and warning that the United States would oppose any European attempts to take over.[43]
To end another war scare with the United Kingdom over the Oregon Country, Polk signed the Oregon Treaty dividing the territory, angering Northern Democrats who felt he was prioritizing Southern expansion over Northern expansion.
In the winter of 1845–46, the federally commissioned explorer John C. Frémont and a group of armed men appeared in Alta California. After telling both the Mexican governor and the American Consul Thomas O. Larkin that he was merely buying supplies on the way to Oregon, he instead went to the populated area of California and visited Santa Cruz and the Salinas Valley, explaining he had been looking for a seaside home for his mother.[44] Mexican authorities became alarmed and ordered him to leave. Frémont responded by building a fort on Gavilan Peak and raising the American flag. Larkin sent word that Frémont's actions were counterproductive. Frémont left California in March but returned and took control of the California Battalion following the outbreak of the Bear Flag Revolt in Sonoma.[45]
In November 1845, Polk sent John Slidell, a secret representative, to Mexico City with an offer to the Mexican government of $25 million for the Rio Grande border in Texas and Mexico's provinces of Alta California and Santa Fe de Nuevo México. U.S. expansionists wanted California to thwart any British interests in the area and to gain a port on the Pacific Ocean. Polk authorized Slidell to forgive the $3 million owed to U.S. citizens for damages caused by the Mexican War of Independence and pay another $25 to $30 million for the two territories.[9][10]
Mexico was neither inclined nor able to negotiate. In 1846 alone, the presidency changed hands four times, the war ministry six times, and the finance ministry sixteen times.[46] Despite that, Mexican public opinion and all political factions agreed that selling the territories to the United States would tarnish the national honor.[47][48] Mexicans who opposed direct conflict with the United States, including President José Joaquín de Herrera, were viewed as traitors.[49] Military opponents of de Herrera, supported by populist newspapers, considered Slidell's presence in Mexico City an insult. When de Herrera considered receiving Slidell to settle the problem of Texas annexation peacefully, he was accused of treason and deposed. After a more nationalistic government under General Mariano Paredes y Arrillaga came to power, it publicly reaffirmed Mexico's claim to Texas.[49]
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.[50] 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."[51] 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."[52] 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."[53]
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.[54]
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[further explanation needed] due to an influx of American settlers[citation needed]. As a result, indigenous populations from the Great Plains region had to rely on raiding American camps in order to survive.[55] 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.[55] By raiding, indigenous populations were also able to acquire horses and properly tame them to move efficiently during battles.[56] 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.[57]
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."[58]
There were significant political divisions in Mexico which seriously impeded the war effort.[59] Inside Mexico, the conservative centralistas and liberal federalists vied for power, and at times these two factions inside Mexico's military fought each other rather than the invading U.S. Army. Santa Anna bitterly remarked, "However shameful it may be to admit this, we have brought this disgraceful tragedy upon ourselves through our interminable in-fighting."[60]
During the conflict, presidents held office for a period of months, sometimes just weeks, or even days. Just before the outbreak of the war, liberal General José Joaquín de Herrera was president (December 1844 – December 1845) and willing to engage in talks so long as he did not appear to be caving to the U.S., but he was accused by many Mexican factions of selling out his country (vendepatria) for considering it.[61] He was overthrown by Conservative Mariano Paredes (December 1845 – July 1846), who left the presidency to fight the invading U.S. Army and was replaced by his vice president Nicolás Bravo (July 28, 1846 – August 4, 1846). The conservative Bravo was overthrown by federalist liberals who re-established the federal Constitution of 1824. José Mariano Salas (August 6, 1846 – December 23, 1846) served as president and held elections under the restored federalist system. General Antonio López de Santa Anna won those elections, but as was his practice, he left the administration to his vice president, who was again liberal Valentín Gómez Farías (December 23, 1846 – March 21, 1847). In February 1847, conservatives rebelled against the liberal government's attempt to take Church property to fund the war effort. In the Revolt of the Polkos, the Catholic Church and conservatives paid soldiers to rise against the liberal government.[62] Santa Anna had to leave his campaign to return to the capital to sort out the political mess.
Santa Anna briefly held the presidency again, from March 21, 1847 – April 2, 1847. His troops were deprived of support that would allow them to continue the fight. The conservatives demanded the removal of Gómez Farías, and this was accomplished by abolishing the office of vice president. Santa Anna returned to the field, replaced in the presidency by Pedro María de Anaya (April 2 – May 20, 1847). Santa Anna returned to the presidency on May 20, 1847, when Anaya left to fight the invasion, serving until September 15, 1847. Preferring the battlefield to administration, Santa Anna left office again, leaving the office to Manuel de la Peña y Peña (September 16 – November 13, 1847).
With U.S. forces occupying the Mexican capital and much of the heartland, negotiating a peace treaty was an exigent matter, and Peña y Peña left office to do that. Pedro María Anaya returned to the presidency on November 13, 1847 – January 8, 1848. Anaya refused to sign any treaty that ceded land to the U.S., despite the situation on the ground with Americans occupying the capital. Peña y Peña resumed the presidency January 8, 1848 – June 3, 1848, during which time the Treaty of Guadalupe Hidalgo was signed, bringing the war to an end.
Polk had pledged to seek expanded territory in Oregon and Texas, as part of his campaign in 1844, but the regular army was not sufficiently large to sustain extended conflicts on two fronts. The Oregon dispute with Britain was settled peaceably by treaty, allowing U.S. forces to concentrate on the southern border.
The war was fought by regiments of regulars bolstered by various regiments, battalions, and companies of volunteers from the different states of the Union, as well as Americans and some Mexicans in California and New Mexico. In general, the Regular Army officers looked down on the volunteers, whose training was poor and whose behavior was undisciplined. (see below)
On the West Coast, the U.S. Navy fielded a battalion of sailors, in an attempt to recapture Los Angeles.[63] Although the U.S. Army and Navy were not large at the outbreak of the war, the officers were generally well trained and the numbers of enlisted men fairly large compared to Mexico's. At the beginning of the war, the U.S. Army had eight regiments of infantry (three battalions each), four artillery regiments and three mounted regiments (two dragoons, one of mounted rifles). These regiments were supplemented by 10 new regiments (nine of infantry and one of cavalry) raised for one year of service by the act of Congress from February 11, 1847.[64] A large portion of this fighting force consisted of recent immigrants. According to Tyler V. Johnson, foreign-born men amounted to 47 percent of General Taylor's total forces. In addition to a large contingent of Irish- and German-born soldiers, nearly all European states and principalities were represented. It is estimated that the U.S. Army further included 1,500 men from British North America, including French Canadians.[65][66]
Although Polk hoped to avoid a protracted war over Texas, the extended conflict stretched regular army resources, necessitating the recruitment of volunteers with short-term enlistments. Some enlistments were for a year, but others were for 3 or 6 months.[67] The best volunteers signed up for a year's service in the summer of 1846, with their enlistments expiring just when General Winfield Scott's campaign was poised to capture Mexico City. Many did not re-enlist, deciding that they would rather return home than place themselves in harm's way of disease, threat of death or injury on the battlefield, or in guerrilla warfare. Their patriotism was doubted by some in the U.S., but they were not counted as deserters.[68] The volunteers were far less disciplined than the regular army, with many committing attacks on the civilian population, sometimes stemming from anti-Catholic and anti-Mexican racial bias.[69] Soldiers' memoirs describe cases of looting and murder of Mexican civilians, mostly by volunteers. One officer's diary records: "We reached Burrita about 5 pm, many of the Louisiana volunteers were there, a lawless drunken rabble. They had driven away the inhabitants, taken possession of their houses, and were emulating each other in making beasts of themselves."[70] John L. O'Sullivan, a vocal proponent of Manifest Destiny, later recalled "The regulars regarded the volunteers with importance and contempt ... [The volunteers] robbed Mexicans of their cattle and corn, stole their fences for firewood, got drunk, and killed several inoffensive inhabitants of the town in the streets." Many of the volunteers were unwanted and considered poor soldiers. The expression "Just like Gaines's army" came to refer to something useless, the phrase having originated when a group of untrained and unwilling Louisiana troops was rejected and sent back by General Taylor at the beginning of the war.[71]
In his 1885 memoirs, Ulysses Grant assesses the U.S. armed forces facing Mexico more favorably.
The victories in Mexico were, in every instance, over vastly superior numbers. There were two reasons for this. Both General Scott and General Taylor had such armies as are not often got together. At the battles of Palo Alto and Resaca-de-la-Palma, General Taylor had a small army, but it was composed exclusively of regular troops, under the best of drill and discipline. Every officer, from the highest to the lowest, was educated in his profession, not at West Point necessarily, but in the camp, in garrison, and many of them in wars with Natives. The rank and file were probably inferior, as material out of which to make an army, to the volunteers that participated in all the later battles of the war; but they were brave men, and then drill and discipline brought out all there was in