The Mexican-American War commenced on May 13, 1846, after President James Knox Polk (1795–1849) pressured Congress for an immediate declaration of war on Mexico. The road to war with Mexico represents a complicated period in U.S. history. By late 1845 political upheaval between the Whigs and the Democrats had reached a crescendo in Congress. The most pressing political issue surrounding war with Mexico had been the potential expansion of slavery to the U.S. Southwest. Many prowar congressional leaders favored battle as a means by which they could increase the influence and lucrative potential of slavery; meanwhile other hawkish war supporters understood the conflict to be a moral struggle for the purpose of spreading freedom and liberty in the absence of servitude. Former president John Quincy Adams (1825–1829), an ardent antislavery advocate, became one of the few voices of dissent in the House of Representatives then dominated by congressmen arguing for war.
By 1803 Texas had become a disputed territory between the United States and Mexico. Many Americans loudly proclaimed Texas a part of the Louisiana Purchase brokered by President Thomas Jefferson on April 30, 1803. In 1821 Mexico achieved independence from Spanish control. Most of the Spanish leaders, pejoratively labeled gachupines, were deposed, and in their place native mestizo rulers assumed control of the government. (Gachupines were native Spaniards who oppressed, enslaved, and exploited indigenous Mexicans. This is a pejorative term referring to Spanish imperialists, similar to the word gringo.) The mestizos became known as criollos, most of whom demonstrated ineptitude due to their initial inexperience at governing, for under Spanish rule few indigenous citizens had achieved positions of power (Faulk and Stout 1973, p. xiii). Political turmoil and chronic factionalism followed the Mexican independence movement. Approximately thirty-six changes in leadership occurred between 1833 and 1855. The military remained dominant in political affairs, a circumstance that facilitated the rise of Mexican general turned president Antonio López de Santa Anna (1794–1876), who was elected president of Mexico by a majority vote in 1833. Santa Anna began his military career in 1810 as a cadet under the command of Joaquín de Arredondo. Mexican historians differ on whether he was vulgar and corrupt or a brave and skillful leader.
Provoked by the aggressive movements of volunteer soldiers from Texas in 1836, the fiery Santa Anna set his sights on attacking Texan forces garrisoned at the Alamo mission in San Antonio. A bloody battle ensued at the Alamo. The most popular American interpretation of this incident depicts a small but death-defying American force of roughly three hundred soldiers led by Sam Houston and Davy Crockett pitted against Santa Anna’s roughly eight thousand bloodthirsty attackers (Mexican historians present a significantly different version of the battle). The battle officially lasted for thirteen days, from February 23 to March 6, 1836. There is some debate as to whether the Mexican general ordered the execution of American forces surrendering peacefully or if the Americans chose to fight until the bitter conclusion. The undeniable historical result of this tragic event is that no Americans were left alive. Consequently Santa Anna became a virtual public enemy in the United States.
While the battle raged at the Alamo, a group of sixty councilmen representing the U.S. citizens of Texas gathered at the “General Convention” in the town of Washington and unanimously declared independence. All sixty signatories to the Texas Declaration of Independence (March 2, 1836), including Sam Houston, declared their independence from the “evil rulers” who brought “oppression” and removed even “the semblance of freedom.”
Compassion among U.S. observers of the Texans’ struggle further developed because of Mexico’s Goliad campaign of 1836 (also referred to as the “Goliad massacre”). This event has taken second place to the Alamo in American memory. One of Santa Anna’s commanders, General José de Urrea (1795–1848), succeeded in taking prisoner 230 American soldiers who surrendered voluntarily on March 20, 1846. Santa Anna betrayed Urrea’s promise of their safety by ordering the execution of many of the unarmed Texas fighters. Their deaths were justified by Santa Anna, who labeled them “foreign pirates” who had attacked a sovereign government without legal cause (Faulk and Stout 1973, p. xv).
At the battle of San Jacinto on April 21, 1836, Santa Anna’s forces suffered defeat at the hands of an outraged Texan army. Santa Anna sought to avoid capture and punishment by dressing in plain clothing and hiding in the fields. Eventually U.S. forces recognized and seized him.
This battle for all intents and purposes secured Texan independence and halted Santa Anna’s onslaught. In 1836 Anglo-Americans residing in Texas declared independence. Mexican leaders immediately recognized the danger in the United States receiving an unfettered pass to annex the former Mexican territory. Many feared the U.S. spirit of expansion would whet the appetite of expansionists in Congress and expedite the annexation movement.
Meanwhile, in order for Mexican leaders to maintain power, they had to continually promise embittered constituents a reconquest of Texas. Mexico refused to acknowledge Texas as an independent state and asserted both its claims to the disputed territory and its willingness to defend against U.S. violation of its sovereignty. Nevertheless, the U.S. government did not express an absolute commitment to sending military forces to defend Texas against an onslaught. This prompted volunteer soldiers, also known as “soldiers of fortune,” to flood into the disputed region (Haynes 2002, p. 115). Despite promises to recover San Antonio and other lost territories, Mexico’s promised assaults failed to materialize. In early 1845 the voters of Texas approved the Annexation Ordinance, which prompted a congressional authorization known as the Joint Resolution to Admit Texas as a State; this was subsequently signed into effect by President Polk on December 29, 1845. Northern abolitionists feared that the admittance of Texas into the Union would encourage the expansion of slavery and destabilize the nation. John R. Collins writes that “a small group of Whig abolitionists … viewed the war as a ‘slavocracy conspiracy’” (Faulk and Stout 1973, p. 70).
Born in Mecklenburg County, North Carolina, in 1795, Polk became president of the United States in 1844. His political platform consisted primarily of a belligerent attitude toward Mexico’s reluctance to relinquish the southwestern territories and an aggressive stance toward Great Britain, who refused to budge on the issue of sharing or relinquishing the Oregon Territory. As a candidate for president, Polk had promised both to reannex Texas and to occupy Oregon from the California boundary to the 54'40” latitudinal line. At this time the theory of manifest destiny was on the rise. The term, coined by the influential Democratic writer and strategist John L. O’Sullivan, addressed the right of the United States to spread freedom and liberty across the North American continent. Supporters of this ideology believed that God, or divine Providence, had empowered the American people with the ability to conquer the continent and thereby civilize and Christianize the world. Although not completely materialized by 1844, the spirit of manifest destiny, teamed with Polk’s campaign promises, seemingly offered a mandate to the incipient president to engage those who stood in America’s pathway to continental dominance.
The United States persisted in its assertion that the Rio Grande represented the legal southern border of Texas, despite the obvious lack of evidence to validate the claim. Polk dispatched minister plenipotentiary John Slidell (1793–1871) to Mexico with the express purpose of settling the border dispute in favor of the Rio Grande rather than the Nueces River, as demanded by the Mexican government. Slidell was also instructed to purchase New Mexico and California. At least two previous presidential administrations, those of John Quincy Adams and Andrew Jackson, had sent negotiators to purchase Texas and possibly the surrounding territories from Mexico; their offers were soundly rejected and seemed only to antagonize Mexican leaders. Polk offered $5 million to redraw the boundary of Texas to the Rio Grande and $25 million for the California Territory. The Mexican government repudiated Slidell and the offer. Consequently President Polk decided to station General Zachary Taylor (1784–1850) with U.S. forces along the Rio Grande. In turn Mexican general Mariano Arista (1802–1855) guarded the Mexican side of the river. Border provocations on April 24 and the refusal of the Mexican government to negotiate with the president’s ambassador instigated war. After President Polk delivered a war message to Congress, the United States officially declared war on Mexico on May 13, 1846.
Combat had already commenced, with Colonel Stephen Kearny’s Army of the West traveling to New Mexico and then to California to secure those territories for U.S. migration and General Zachary Taylor’s army crushing the Mexican forces in battles at Palo Alto and Resaca de Palma. Kearny fully controlled Santa Fe by August 18, 1846. In California a group of American settlers, along with an exploring party led by John C. Frémont (1813–1890), joined Kearny in what became known as the “Bear Flag Revolution” (Brinkley 2003, p. 352). U.S. soldiers experimented with flying artillery at Palo Alto, and hand-to-hand fighting erupted at Resaca de Palma. The U.S. Navy seized control of Monterey and Los Angeles thanks to Commodore John Drake Sloat (1781–1867). During these tempestuous days of battle, the former Mexican general Santa Anna returned from exile to prepare an army of roughly twenty thousand men with the express purpose of fighting the invaders until any defense would become untenable. Enthusiasm for war in the United States led to 200,000 volunteers responding to the secretary of war’s call to arms (Haynes 2002, p. 155).
U.S. forces entered battle outnumbered in almost every engagement with Mexico (Eisenhower 1986, p. 35). The most recognizable casualties of war were “Henry Clay, Jr., and Archibald Yell, former governor of Arkansas (both at Buena Vista), and Captain Samuel Walker of the Texas Rangers, at Huamantia” (Eisenhower 1986, p. 36). Volunteer forces received only a rudimentary training, and due to the sporadic popularity of the war, many of the soldiers, themselves from different states, never trained together. Many of the volunteers were not supplied with the bare essentials, and this led to sickness and disease. Statistically the greatest challenge to the army, and the most damage inflicted on it, was caused by outbreaks of disease. Of the approximately 100,182 soldiers who fought in the war, nearly 10,790 died from disease and exposure to inclement weather. A much smaller number, 1,548 volunteers, died on the battlefield. Generals George B. McClellan (1826–1885) and Winfield Scott (1786–1866) marveled at the destruction wrought on their forces by rampant diseases. The historian Thomas Irey asserts that nearly 10 percent of all “noncombat” deaths were caused by disease and infection (Faulk and Stout 1973, p. 110). President Polk’s troubled relationships with generals Scott and Taylor further challenged the U.S. military’s already troubled tactics (Haynes 2002, p. 152). On November 19, 1846, the president reap-pointed General Scott commander of the army, displacing Taylor.
On March 9, 1847, General Scott landed at Veracruz with ten thousand soldiers, finally entering Mexican territory to compel surrender. Scott eventually advanced 260 miles across the Mexican National Highway to Mexico City. This major amphibious assault was the first of its kind in U.S. history (Brinkley 2003, p. 352). On April 18 Scott’s forces pushed forward at Cerro Gordo, flanking Santa Anna’s forces and forcing his retreat, embarrassingly without his artificial leg. Some of the most famous future Civil War generals planned this mission, including Robert E. Lee (1807–1870), McClellan, Joseph E. Johnston (1807–1891), and P. G. T. Beauregard (1818–1893). At Churubusco on August 20, Scott’s army defeated a Mexican defensive force of twenty thousand soldiers. The last major confrontation before Scott’s forces marched on Mexico City was the battle of Molino del Rey, in which twelve thousand Mexican soldiers lost the battle and the overall struggle and Scott took Chapultepec, overlooking Mexico City. Nevertheless, by September 1847 many Americans had become frustrated by Mexico’s refusal to accept terms of surrender (Davis 1999, p. 316).
In the summer of 1847 Mexico received Polk’s special peace envoy Nicholas P. Trist (1800–1874). In July, Mexico stalled, then rebuffed the ambassador’s offer. Although Polk recalled Trist and sought to demand more from Mexico, on February 2, 1848, the Treaty of Guadalupe Hidalgo was negotiated by the envoy. The treaty ceded to the United States 500,000 miles of Mexican territory that would become the U.S. states of New Mexico, California, Arizona, Nevada, Wyoming, and Colorado (Davis 2003, p. 192). Mexico also conceded that the Rio Grande would become the permanent border of Texas. The United States compensated Mexico with $15 million in exchange for the lost territory and $3.25 million in remuneration. The Senate ratified the treaty by a vote of 38 to 14 on March 10, 1848 (National Archives 2003, p. 72).
More so than the Mexican-American War itself, the events that roused the bellicose passions of the American people have been captured in cinematic history. Walt Disney produced a three-episode television series about Davy Crockett that included Davy Crockett at the Alamo (1955), a romantic story depicting a group of outnumbered Americans surrounded by a marauding army waiting to pummel them. There also have been more than twenty major motion pictures produced about Crockett’s famous execution after or death in battle at the Alamo. In 1960 John Wayne directed and starred as Crockett in The Alamo. In 2004 Billy Bob Thornton starred as Crockett in another film titled The Alamo alongside Dennis Quaid, who was cast as General Sam Houston. Most of the films on this subject depict a mythologized version of historical events.
Many political theorists point to U.S. imperialism and the insatiable southern drive to further the institution of slavery as the motivations for war with Mexico. Utilizing the writings of the then-congressman Abraham Lincoln, some political scientists assert that Mexican provocations led to the shedding of American blood to be sure but on the Mexican side of the border, thus negating the American claim that Mexico had trespassed on U.S. soil illegally, prompting the U.S. declaration of war. More traditional historians assert that the Mexican leadership believed their nation to be omnipotent because of their enormous success in expelling the Spanish leadership and that, given Britain’s inclination to stir up trouble in the region in order to attain California and to retain the Oregon territories, Mexican leaders felt assured of their assistance should their own forces suffer serious setbacks. The British never offered such assistance.
According to the historian Kyle Ward, who examines changes in the content of textbooks on U.S. history, late-twentieth-century American political scientists portrayed the U.S. South in a detestable light, alleging that a plot existed to encompass all of Mexico’s territory into their slavocracy (Ward 2006, p. 158). Following this line of logic, many historians believe that President Polk and his cohorts would have seized more territory and imposed a harsher indemnity on Mexico if there had not been such widespread domestic and congressional opposition to his policy of expansion. This is why, according to some, Polk never requested a straightforward yes or no vote on the war (Silverstone 2004, p. 198). In lieu of an up-or-down vote, the president asked for reinforcements and war materials for a war that had already been provoked and threatened to engulf the U.S. territory if Congress failed to act quickly and decisively.
Brinkley, Alan. 2003. American History: A Survey. Boston: McGraw-Hill.
Davis, Kenneth C. 2003. Don’t Know Much about History. New York: HarperCollins.
Eisenhower, John S. D. 1986. Polk and His Generals. In Essays on the Mexican War, ed. Douglas W. Richmond, John S. D. Eisenhower, Miguel E. Soto, and Wayne Cutler, 34–65. College Station: Texas A&M Press.
Faulk, Odie B., and Joseph A. Stout Jr. 1973. The Mexican War: Changing Interpretations. Chicago: Sage.
Haynes, Sam W. 2002. James K. Polk and the Expansionist Impulse. New York: Longman.
Silverstone, Scott A. 2004. Divided Union: The Politics of War in the Early American Republic. Ithaca, NY: Cornell University Press.
Ward, Kyle. 2006. History in the Making: An Absorbing Look at How American History Has Changed in the Telling over the Last 200 Years. New York: New Press.
Jonathan A. Jacobs
When James Knox Polk opened his presidential campaign in 1844, he promised to enlarge the United States by annexing the Oregon territory and the Republic of Texas, disregarding the fact that Mexicans believed Texas still to be part of their nation. Polk's promise was merely the latest salvo in a long campaign of U.S. territorial aggrandizement that some have characterized as "manifest destiny." Following his election and the settlement of the Oregon issue, the United States Congress voted to annex Texas in 1845.
Upon hearing the news, Mexicans charged that their sovereignty had been violated. Months of negotiations and threats between the two nations failed to resolve the issue. Major General Mariano Paredes appealed to Mexicans' frustration with this lingering issue and seized power from General José Joaquín de Herrera, contending that he failed adequately to defend Mexican honor. With Paredes in power, Mexico intensified its preparations to assert its sovereignty over Texas, mobilizing troops near the mouth of the Rio Grande, avoiding the disputed territory between it and the Nueces River, the traditional border of Texas. Meanwhile, President Polk appointed John C. Slidell as negotiator with orders to buy California. Slidell's offers infuriated Mexican officials, who rebuffed him. Simultaneously, U.S. warships were sighted in Mexican waters near Veracruz. On 23 June 1845, Brevet Brigadier General Zachary Taylor, commanding approximately 1,500 regulars, left Fort Jesup, Louisiana, for Texas. Mexican intelligence reports revealed that by the end of July 1845, Taylor and his army had camped at Corpus Christi, near the mouth of the Nueces. On 8 March 1846, after Slidell's failure to purchase Mexican land, Polk ordered Taylor to move his troops southward to Point Isabel, into disputed territory. Another detachment had been moved to Fort Texas, opposite Matamoros. By April, the 2,200-man U.S. army was well established in southern Texas; the Mexicans made no attempt to dislodge them. On 4 April 1846, General José María Tornel y Mendivil, minister of war, appointed Major General Mariano Arista to command the Army of the North. Proceeding from Monterrey to Matamoros, Arista mobilized an army of 5,200 troops. In the first week of May, the two nations stood on the brink of war.
Events began to move swiftly in south Texas. On 24 April a clash had taken place at Carricitos, where Mexican troops had routed a U.S. detachment. And between 3 and 9 May, Fort Texas had suffered casualties from the intermittent bombardments by Mexican artillery. Although several U.S. troops, including Major Jacob Brown, for whom Brownsville was later named, had been killed in the encounter, it was the skirmish at Carricitos that furnished the circumstances that Polk used to ask Congress for a declaration of war, claiming that U.S. blood had been shed on U.S. soil. Congressman Abraham Lincoln challenged his colleagues to show him where in U.S. territory that had occurred. By 11 May, two days after Taylor's communiqué had arrived in Washington, the House of Representatives approved a bill authorizing war against Mexico. The next day the Senate voted in favor of war, and on 13 May, Polk signed the measure.
Meanwhile, on the flat plains of Texas, as Taylor attempted to reinforce Fort Texas, he was blocked at Palo Alto by the Mexican army. Just after noon on 8 May, the Battle of Palo Alto, the first major engagement of the Mexican-American War, began. Taylor pitted his 2,200 troops against 3,200 Mexican soldiers under Arista. The Mexican battle line was a mile and a quarter long; the U.S. army was deployed in smaller units. U.S. horsedrawn "flying" artillery dominated the battle, and the Mexican army sustained heavy casualties. The next day, at the Battle of Resaca de la Palma, the Mexicans were routed and sent reeling back to Matamoros. Within days, Matamoros fell to the advancing U.S. army (18 May), and Arista retreated to Linares, where he was relieved of command.
General Pedro Ampudia was given command and decided to make a stand at Monterrey, a city surrounded by natural barriers. While Ampudia was preparing the defenses, Paredes was overthrown in Mexico City by the liberals, headed by Valentín Gómez Farías, and Antonio López de Santa Anna returned from exile. Ampudia, perhaps influenced by the fall of his patron, frequently changed his plans to defend Monterrey, thus confusing and demoralizing his army. Taylor assaulted Monterrey in September with unceasing artillery barrages. Initially the battle went poorly for the U.S. troops, but they successfully outflanked the Mexican defenses. The Mexican defensive perimeter began to shrink. Numerous civilians were trapped inside the city and were killed. In order to win the city, Taylor had agreed to permit the Mexican army to march out with a limited amount of war matériel. Monterrey surrendered on 25 September.
By late 1846, U.S. troops had captured all of northern Mexico as far south as Monterrey with few exceptions and held the initiative. However, Mexico showed no signs of suing for peace. U.S. forces believed it impractical to cross the desert south of Monterrey, so they decided to halt the offensive in the north and to attack Veracruz and drive on to Mexico City. To accomplish this, Taylor was ordered to send the best half of his army (the regulars) to join Winfield Scott, who had been selected to attack Veracruz.
General Antonio López de Santa Anna, now commanding the Mexican army, intercepted a dispatch that outlined this plan. In response, he boldly led his ill-prepared troops northward from San Luis Potosí in an attempt to catch Taylor by surprise. The two armies met at Buena Vista in February 1847, and again the U.S. artillery was too much for the Mexican army, and Santa Anna was defeated. He now rushed south in order to put down a rebellion in Mexico City and to meet Scott's army, which was advancing from Veracruz.
Mexico had not fared any better with the campaigns in the northwest and the south. In the north, Brigadier General Stephen Watts Kearny and the Army of the West had seized New Mexico, and next prepared to march through Arizona to capture California, which was already in turmoil. Northern California resisted the efforts of John C. Frémont, while in southern California, Andrés Pico and his lancers almost annihilated Kearny at San Pascual, near San Diego. Meanwhile, Colonel Alexander William Doniphan's sweep from New Mexico through Chihuahua, Nuevo León, and Tamaulipas and back through Mier, Camargo, and Reynosa had seriously impaired Mexico's ability to mount any form of counterattack. Having taken the port of Veracruz following a bloody bombardment on 29 March 1847, Scott's inland victories at Cerro Gordo, Contreras, Churubusco, and Molino del Rey demonstrated how ill prepared Mexico was for war, particularly its lack of modern weaponry and ammunition. After a short but stiff resistance by the Niños Héroes at Chapúltepec, U.S. forces entered Mexico City. Finally, on 14 September 1847, Scott entered the capital and took possession. Mexican resistance continued for a short time at Puebla, Huamantla, Atlixco, and other places through which American supplies and reinforcements passed. Throughout the winter of 1847–1848 peace talks continued that resulted in the Treaty of Guadalupe Hidalgo. With the acceptance of the treaty, the war came to an end and the United States emerged victorious, having wrested away half of Mexico's land. Mexico's losses included the present states of Arizona, California, Colorado, Nevada, New Mexico, and Utah in addition to Texas. The United States paid Mexico $15 million and assumed the responsibility for $3.5 million in claims by U.S. citizens against the Mexican government. Mexicans living in the ceded territories were to be treated as citizens of the United States. The treaty was ratified on 10 March 1848 by the United States and 19 May 1848 by Mexico.
See alsoAmpudia y Grimarest, Pedro de; Arista, Mariano; Frémont, John Charles; Gómez Farías, Valentín; Guadalupe Hidalgo, Treaty of (1848); Herrera, José Joaquín Antonio Florencio; Kearny, Stephen W.; Monterrey; Niños Héroes; Paredes y Arrillaga, Mariano; Polk, James Knox; Santa Anna, Antonio López de; Taylor, Zachary; Tornel y MendÚvil, José María.
In addition to such classical books as Apuntes para la guerra entre México y los Estados Unidos (Notes on the War between Mexico and the United States) by Manuel Payno, Guillermo Prieto, and other witnesses to the events, significant contributions have been made in more recent years to the study of this war, focusing on the advance of the U.S. troops and the defense put up by the Mexicans. On the subject of the resistance offered by Mexico City, the most original and interesting may be Sueñan las piedras: alzamiento ocurrido en la ciudad de México, 14, 15 y 16 de septiembre (The Stones Are Dreaming: The Uprising in Mexico City, September 14, 15, and 16) by Luis Fernando Granados (Mexico: Era, National Institute of Anthropology and History, 2003). On the subject of tensions between the Mexican leaders, the defense battles, and how the U.S. army reached Mexico City's main square, there is Crónica del 47 (Chronicle of '47) by José Emilio and Andrés Reséndiz (Mexico: Clío, 1997). For a more general overview, focusing on the military movements and other aspects, there are the books written by Josefina Zoraida Vázquez: México al tiempo de su guerra con Estados Unidos (1846–1848) (Mexico in the Time of War with the United States: 1846–1848, México: Fondo de Cultura Económica, Secretaría de Relaciones Exteriores, El Colegio de México, 1997) and La intervención norteamericana (The North American Intervention, México: Secretaría de Relaciones Exteriores, 1997). The more recent studies also include a highly interesting compilation of letters sent from all the states in the Mexican Republic, dealing with their defense against the invading army. The best is Testimonios de una Guerra: México 1846–1848 (Testimonies of a War. Mexico: 1846–1848) by Mercedes de Vega and María Cecilia Zuleta (Mexico: Secretaría de Relaciones Exteriores, 2001).
Joseph P. SÁnchez
VÍctor Villavicencio (Bibliography)
MEXICAN-AMERICAN WAR (1846–1848). The war's remote causes included diplomatic indiscretions during the first decade of American-Mexican relations, as well as the effects of the Mexican revolutions, during which American citizens suffered physical injury and property losses. Its more immediate cause was the annexation of Texas. The Mexican government refused to recognize Texas as independent or the Rio Grande as an international boundary. It first withdrew its minister from Washington, D.C., and then severed diplomatic relations in March 1845.
President James K. Polk anticipated military action and sent Brigadier General Zachary Taylor with his force from Louisiana to the Nueces River in Texas, but he also sought a diplomatic solution. Recognizing that the chief aim of American foreign policy was the annexation of California, Polk planned to connect with that policy the adjustment of all difficulties with Mexico, including the dispute over jurisdiction in the territory between the Nueces River and the Rio Grande.
In September 1845, assured through a confidential agent that the new Mexican government of José Joaquín Herrera would welcome an American minister, and acting on the suggestion of Secretary of State James Buchanan, Polk appointed John Slidell as envoy-minister on a secret mission to secure California and New Mexico for $15 million to $20 million if possible, or for $40 million if necessary—terms later changed by secret instructions to $5 million for New Mexico and $25 million for California.
Mexico refused to reopen diplomatic relations. In January 1846, after the first news that the Mexican government, under various pretexts, had refused to receive Slidell, partly on the ground that questions of boundary and claims should be separated, Polk ordered Taylor to advance from Corpus Christi, Texas, to the Rio Grande, resulting shortly in conflicts with Mexican troops at the battle of Palo Alto on 8 May and the battle of Resaca de la Palma on 9 May. On 11 May, after arrival of news of the Mexican advance across the Rio Grande and the skirmish with Taylor's troops, Polk submitted to Congress a war message stating that war existed and that it was begun by Mexico on American soil. The United States declared war on 13 May, apparently on the ground that such action was justified by the delinquencies, obstinacy, and hostilities of the Mexican government; and Polk proceeded to formulate plans for military and naval operations to advance his goal of obtaining Mexican acceptance of his overtures for peace negotiations.
The military plans included an expedition under Colonel Stephen W. Kearny to New Mexico and from there to California, supplemented by an expedition to Chihuahua; an advance across the Rio Grande into Mexico by troops under Taylor to occupy the neighboring provinces; and a possible later campaign of invasion of the Mexican interior from Veracruz.
In these plans Polk was largely influenced by assurances received in February from Colonel A. J. Atocha, a friend of Antonio López de Santa Anna, then in exile from Mexico, to the effect that the latter, if aided in plans to return from Havana, Cuba, to Mexico, would recover his Mexican leadership and cooperate in a peaceful arrangement to cede Mexican territory to the United States. In June, Polk entered into negotiations with Santa Anna through a brother of Slidell, receiving verification of Atocha's assurances. Polk had already sent a confidential order to Commodore David Conner, who on 16 August permitted Santa Anna to pass through the coast blockade to Veracruz. Having arrived in Mexico, Santa Anna promptly began his program, which resulted in his own quick
restoration to power. He gave no evidences whatever of his professed pacific intentions.
On 3 July 1846 the small expedition under Kearny received orders to go via the Santa Fe Trail from Fort Leavenworth, Kansas, to occupy New Mexico. It reached Santa Fe on 18 August, and a part of the force (300 men) led by Kearny marched to the Pacific at San Diego. From there it arrived at Los Angeles to join the forces led by Commodore Robert Field Stockton, including John Charles Frémont's Bear Flag insurgents. Kearny and Stockton joined forces and defeated the Mexican army at Los Angeles on 8 and 9 January 1847. On 13 January, Frémont and Andres Pico, the leader of the Mexican forces in California, signed the Treaty of Cahuenga. Kearny went on to establish a civil government in California on 1 March.
Taylor's forces, meanwhile, began to cross the Rio Grande to Matamoros on 18 May 1846 and advanced to the strongly fortified city of Monterrey, which after an attack was evacuated by Mexican forces on 28 September. Later, in February 1847 at Buena Vista, Taylor stubbornly resisted and defeated the attack of Santa Anna's Mexican relief expedition.
Soon thereafter the theater of war shifted to Veracruz, from which the direct route to the Mexican capital seemed to present less difficulty than the northern route. In deciding on the campaign from Veracruz to Mexico City, Polk probably was influenced by the news of U.S. occupation of California, which reached him on 1 September 1846. The U.S. Navy had helped secure Monterrey, San Diego, and San Francisco in California and had continued blockades against Veracruz and Tampico. The Navy provided valuable assistance again when General Winfield Scott began a siege of Veracruz. After the capture of the fortress of Veracruz on 29 March 1847, Scott led the army westward via Jalapa to Pueblo, which he entered on 15 May and from which he began his advance to the mountain pass of Cerro Gordo on 7 August.
Coincident with Scott's operations against Veracruz, Polk began new peace negotiations with Mexico through a "profoundly secret mission." On 15 April, Buchanan had sent Nicholas P. Trist as a confidential peace agent to accompany Scott's army. In August, after the battles of Contreras and Churubusco, Trist arranged an armistice through Scott as a preliminary step for a diplomatic conference to discuss peace terms—a conference that began
on 27 August and closed on 7 September by Mexican rejection of the terms offered. Scott promptly resumed his advance. After hard fighting from 7 to 11 September at the battles of Molino del Rey and Chapultepec, he captured Mexico City on 14 September and with his staff entered the palace, over which he hoisted the American flag.
Practically, the war was ended. Santa Anna, after resigning his presidential office, made an unsuccessful attempt to strike at the American garrison Scott had left at Pueblo, but he was driven off and obliged to flee from Mexico.
The chief remaining American problem was to find a government with enough power to negotiate a peace treaty to prevent the danger of American annexation of all Mexico. Fortunately, Trist was still with the army and in close touch with the situation at the captured capital. Although recalled, he determined to assume the responsibility of remaining to renew efforts to conclude a peace treaty even at the risk of disavowal by his government. After some delay, he was able to conclude with the Mexican commissioners a treaty in accord with the instructions that had been annulled by his recall. The chief negotiations were conducted at Mexico City, but the treaty was completed and signed on 2 February 1848 at the neighboring town of Guadalupe Hidalgo. By its terms, which provided for cessation of hostilities, the United States agreed to pay $15 million for New Mexico and California. Polk received the treaty on 19 February and promptly decided to submit it to the Senate, which approved it on 10 March by a vote of thirty-eight to fourteen. Ratifications were exchanged on 30 May 1848.
Among the chief results of the war were expansion of American territory; a new population called Mexican Americans; increased American interest in the problems of the Caribbean and the Pacific and in the opening and control of isthmian interoceanic transit routes at Panama, Nicaragua, and Tehuantepec; and outbursts of "manifest destiny" from 1848 to 1860. The acquisition of Mexico's northern lands also intensified debates over the extension of slavery into new territory and brought the Union a step closer to war.
McCaffrey, James M. Army of Manifest Destiny: The American Soldier in the Mexican War, 1846–1848. New York: New York University Press, 1992.
Robinson, Cecil, ed. and trans. The View from Chapultepec: Mexican Writers on the Mexican-American War. Tucson: University of Arizona Press, 1989.
Smith, George W., and Charles Judah, eds. Chronicles of the Gringos: The United States Army in the Mexican War, 1846–1848. Albuquerque: University of New Mexico Press, 1968.
J. M.Callahan/f. b.
See alsoHispanic Americans ; Kearny's March to California ; Manifest Destiny ; Navy, United States ; andvol. 9:Memories of the North American Invasion ; Mexican Minister of War's Reply to Manuel de la Peña y Peña ; National Songs, Ballads, and Other Patriotic Poetry, Chiefly Relating to the War of 1846 ; Message on the War with Mexico .
The Mexican-American War (1846–48) achieved U.S. expansionist goals by adding more than one million square miles to the United States—the present-day states of New Mexico , Arizona , and California and portions of Colorado , Nevada , Wyoming , and Utah . Mexico's defeat plunged the nation into political and economic upheaval for many of the remaining years of the nineteenth century.
The annexation (adding to the nation) of Texas to the United States in 1845 was the main cause of the Mexican-American War. Texas had won its independence from Mexico in the Texas Revolution (1835–36). During this conflict, Texas received aid and soldiers from the United States. Mexican officials blamed their own defeat on this U.S. assistance to Texas. Mexico refused to recognize its independence, believing that someday Texas would return to the Mexican nation—but only if the United States did not annex it. In 1843, President Antonio López de Santa Anna (1794–1876) of Mexico warned that a U.S. annexation of Texas would be the same as declaring war against Mexico.
Annexation of Texas
The United States recognized Texan independence in 1837. Texas sought annexation by the United States, and many Americans wanted to annex the territory, even if it meant war. Until 1845, the annexation had been successfully blocked by antislavery forces who feared the addition of another slave state to the Union.
In 1844, Texas Republic president Sam Houston (1793–1863) negotiated with the U.S. government about the annexation. A treaty was proposed to the Senate, but it was rejected. Meanwhile, the Democratic Party convention nominated an ardent expansionist, James K. Polk (1795–1849; served 1845–49), for president. In its campaign platform, the Democratic Party advocated the annexation of Texas and the acquisition of Oregon. When Polk won the election, outgoing president John Tyler (1790–1862; served 1841–45) and Congress passed a resolution offering to annex Texas, which was signed three days before Polk took office. Mexico promptly broke off diplomatic relations with the United States.
Texas formally entered the Union in December 1845, but an explosive question remained to be settled with Mexico about Texas's boundary. President Polk supported Texas's questionable claim that the Rio Grande River was its southwestern frontier; Mexico claimed the border was at the Nueces River farther north. In June, Polk ordered Brigadier General Zachary Taylor (1784–1850) to move his forces into the disputed area.
In the borderlands
By July 1845, Taylor had established a base on the south bank of the Nueces near Corpus Christi. In November, upon learning that the Mexican government was prepared to discuss the boundary issue, Polk sent Louisiana politician John Slidell (1793–1871) to Mexico with instructions to discuss the border with Texas and two other outstanding issues: the purchase of California and the purchase of New Mexico Territory (made up of parts of present-day New Mexico, Arizona, Colorado, and Nevada). Slidell was authorized to offer $25 million for California and $5 million for New Mexico.
Slidell reached Mexico City on December 6, 1845. The Mexican government, in response to growing Mexican opposition to negotiations with the Americans, refused to receive him. On January 13, 1846, Polk ordered Taylor to advance through the disputed territory, from the Nueces River down to the Rio Grande. Meanwhile, a new Mexican government came into power that reaffirmed Mexico's claim to Texas and refused to receive Slidell.
The battle begins
As Polk and Congress prepared to make a formal declaration of war against Mexico, news arrived from Taylor that a large Mexican force had crossed the Rio Grande and surrounded a small unit of U.S. soldiers; eleven Americans were killed and the rest were wounded or captured. A declaration of war was issued on May 13, 1846. Already, Taylor had fought and won the battles of Palo Alto and Resaca de la Palma, and on May 18 he occupied the Mexican town of Matamoros.
The U.S. declaration of war authorized a call-up of 50,000 volunteers and more than doubled the strength of the regular army from 7,200 to 15,540. The undisciplined volunteers were at times troublesome and did not always represent the United States well. A small portion of the young men murdered, robbed, and raped the Mexican people throughout the war in Mexico.
Polk's initial strategy was to occupy Mexico's northern provinces, blockade Mexican ports, and conquer New Mexico and California. By September, Taylor's army had taken Monterrey in northern Mexico, and by January 1847 American forces in the West had secured New Mexico and California. Although successful militarily, the strategy failed to bring Mexico to terms; in order to do so, Polk decided to shift the major military effort from the north to the heart of the country. The plan called for Major General Winfield Scott (1786–1866) to take Veracruz, a state in eastern Mexico. From there, he could march through the mountains and capture Mexico's capital, Mexico City.
American forces entered Veracruz on March 29, 1847, following a week-long land and naval bombardment (constant shooting with large guns and cannons). On April 8, Scott's army set out along the National Road for the Valley of Mexico, in central Mexico. Mexico once again had a new government and General Santa Anna had once again taken over the presidency. In September, he had taken an army north to oppose Taylor but had been defeated at Buena Vista in February 1847. Having returned to central Mexico, he now prepared to drive back Scott's invasion.
On April 18, Scott defeated Santa Anna at Cerro Gordo, a mountain pass near Veracruz, and on May 15 he reached the city of Puebla, only seventy-five miles from Mexico City. After a delay, Scott resumed the advance, again defeating Santa Anna's forces at Contreras, Churubusco, Molino del Rey, and Chapultepec. He entered the capital in mid-September. Santa Anna fled the country, and the new Mexican president informed Polk that he was prepared to negotiate.
The results of the war
The U.S. Senate ratified the Treaty of Guadalupe Hidalgo on March 10, 1848, bringing an official end to the war. According to the treaty, Mexico relinquished New Mexico and California, an addition of 500,000 square miles to U.S. territory. The U.S.-Mexico boundary was established in the middle of the Rio Grande. In return, the United States paid Mexico $15 million. During negotiations, U.S. leaders assumed an attitude of moral superiority. They viewed the forcible incorporation of almost one-half of Mexico's national territory as their divine right, fulfilling the Manifest Destiny , or divine right to expand, of the United States.
The Treaty of Guadalupe Hidalgo looms large in the history of Mexico. After the war, Mexico experienced decades of political turmoil. Partly because of the loss of valuable territory, the treaty ensured that Mexico would remain an underdeveloped country well into the twentieth century. Mexican historians and politicians view this treaty as a bitter lesson in U.S. aggression.
The war with Mexico was one of the deadliest conflicts in U.S. history in terms of deaths per thousands of men who served. Of more than one hundred thousand U.S. soldiers, sailors, and marines who fought in the war, about fifteen hundred were killed in action, and another eleven thousand died from diseases and wounds.