Study Guide

Manifest Destiny & Mexican-American War People

  • James K. Polk

    James K. Polk (1795–1849) was the 11th President of the United States. His name is perhaps most closely associated with Manifest Destiny, as the term was coined by a fellow Democrat in 1843, the year before he began his presidency. Manifest Destiny—the belief that Americans were destined by God to conquer the continent to the Pacific Ocean—soon came to embody the governing philosophy of the Polk administration and its ardently expansionist aims.

    Polk successfully campaigned on an expansionist platform and vowed not to compromise with the British on the dispute over the Oregon Territory's northern border. Two days after he took office, however, diplomatic relations between Mexico and the United States were severed over the American annexation of Texas. Tensions continued to escalate as Polk settled the Oregon boundary with Britain at 49ºN, far south of the initial demand of "54º40' or fight," angering Northern Democrats who were jealous of the imminent territorial gains to the south. 

    In May 1846, Polk convened his Cabinet and obtained its approval for sending a message of war against Mexico to Congress. The entire premise for the war was controversial from the start and widely decried by Polk's Whig opponents in Congress, though most of them didn't dare vote against bills to provide supplies for the troops. 

    In March 1847, Polk sent Nicholas P. Trist, the chief clerk in the State Department, to Mexico along with Gen. Winfield Scott's troops in order to commence treaty negotiations. Against Polk's orders and amidst great unrest, Trist signed the Treaty of Guadalupe Hidalgo in early February 1848. Polk had wanted more land cessions—in addition to California and the Southwest—but was forced to "settle" for what Trist's treaty got him: California, Nevada, Utah, most of New Mexico and Arizona, and the disputed regions of Texas. In all, it was the largest single land acquisition since the Louisiana Purchase in 1803.

  • Winfield Scott

    General Winfield Scott (1786–1866) was a prominent military figure through three wars and the unsuccessful Whig candidate for president in 1852. He fought in the War of 1812 and the Mexican-American War, and retired shortly after the outbreak of the Civil War

    President Andrew Jackson dispatched him to Charleston, South Carolina in 1832 to quell the nullification crisis. He also supervised the removal of the Cherokee from Georgia along the "Trail of Tears" to Indian Territory (present-day Oklahoma). After landing at Veracruz in 1847, Scott became the first American officer to lead the invasion of a foreign capital when he took Mexico City in September 1847.

    In the Mexican-American War, Scott commanded the southern prong of attack. With the help of the Navy, it didn't take long for him to conquer the Mexican port of Veracruz—his troops marched toward Mexico City and took Cerro Gordo in April, stalled for several months in Puebla, but then advanced victoriously through battles at Contreras and Churubusco. They stormed the heavily fortified castle on a hill known as Chapultepec, and after a day of fighting, they conquered it on September 13th, 1847, opening the way to the capital. 

    The Mexican campaign emphasized the general's boldness and daring strategy. Though the war made Scott a national hero, the Whig supporter's political opponents in the Democratic Polk administration recalled him in early 1848.

  • Stephen W. Kearny

    General Stephen W. Kearny (1794–1848) was Commander of the Army of the West during the Mexican-American War.

    In August 1846, Kearny's force of about 1,600 soldiers occupied Santa Fe and organized a new civil government for New Mexico, promising a democratic administration. Kearny then moved on to Southern California, but was told that Commodore Robert F. Stockton and Lieutenant Colonel John C. Frémont had already conquered the region for the United States. 

    Kearny's depleted force was then besieged at San Pasqual and Kearny discovered that Californios (Mexican citizens of California) had retaken much of the region. By early 1847, Kearny had combined forces with Commodore Robert F. Stockton and squashed the uprising. Kearny served as military governor of the California territory until the end of May 1847.

  • Zachary Taylor

    General Zachary Taylor (1784–1850) commanded the northern campaign in the Mexican-American War and later became the 12th President of the United States. 

    President Polk ordered General Taylor to approach the Rio Grande after the U.S. annexed Texas in late 1845. In April 1846, Mexican soldiers intercepted a small patrol of Taylor's soldiers, killing 16 Americans. The incident became Polk's justification for sending a war bill to Congress.

    Taylor had enormous military successes against the Mexicans at Palo Alto and subsequently at Resaca de la Palma. His forces then surrounded the Mexican stronghold at Monterrey, forcing General Pedro Ampudia to surrender. Infuriated by Taylor's lenient treatment of those Mexican forces, Polk transferred Taylor's forces to join Gen. Winfield Scott's invasion of central Mexico at Veracruz. To capitalize on the resulting upheaval in troop assignments, Mexican General Antonio Lopez de Santa Anna headed north from San Luis Potosí with an army of 20,000 men and attacked, but Taylor's reserves under Colonel Jefferson Davis—later to become the President of the Confederacy—successfully stalled Mexican forces. 

    Late in February 1847, Taylor ordered a counter-attack that halted the Mexican offensive by nightfall. This victory at Buena Vista made Taylor a popular hero, much to Polk's chagrin, and Taylor was nominated for President on the Whig ticket in 1848. He was elected and assumed office in 1849.

  • John C. Frémont

    Captain John C. Frémont (1813–1890) was an American explorer, soldier, and the first—though unsuccessful—Republican Party candidate for the presidency in 1856.

    With the help of his powerful father-in-law, Frémont secured the command of expeditions exploring the West, from the Des Moines River to the Rocky Mountains and Oregon, Nevada, and California country. In 1846, Frémont persuaded the local American residents in California to follow the Texans' example by establishing their own independent Bear Flag Republic at Sonoma. The short-lived experiment accomplished very little. 

    After Stephen W. Kearny and Commodore Robert Stockton claimed California for the U.S. during the Mexican-American War, an argument ensued over who was in command. Frémont sided with Stockton, but the U.S. government sent orders siding with Kearny, who had Frémont arrested, court-martialed, and convicted. President Polk remitted the sentence, but the proud Frémont resigned from government service after that. 

    After making millions from the discovery of gold and serving briefly as a senator, he made an unsuccessful presidential run with the new Republican Party in 1856. The party shared his firm stance against slavery's extension into the West. Employing the slogan, "Free soil, free speech, free men, Fremont," he and the Republicans came closer than anyone had before to uniting the voters of the North and the West against the South. Frémont went on to command the Western Department of the Union Army during the Civil War, but soon left that post. He lost his fortune trying to build a railroad to the Pacific in the 1870s.

  • Henry David Thoreau

    Henry David Thoreau (1817–1862) was an author, essayist, naturalist, and poet whose work went on to influence some of the greatest literary figures of the 20th century. 

    Thoreau expounded upon his love of nature and the doctrines of transcendentalism in Walden (1854), and passionately defended civil liberties and pacifistic protest in the essay "Civil Disobedience" (1849). His friend and mentor was Ralph Waldo Emerson, one of the most prominent intellectuals of the 19th century.

    Thoreau's essay, "Civil Disobedience," emerged out of his experience opposing the Mexican-American War. He'd refused to pay a poll tax as a demonstration against what he felt to be an unjust, imperialistic war and a government waging it to expand slavery's domain. He spent the night in jail before someone paid the tax to set him free. In his essay, Thoreau argued that not all civil laws are just, and that humans have an obligation to obey a higher law—their sense of morality. If obeying the conscience necessitates violating the law, then so be it. Thoreau advocated that others who disapprove of the war follow his lead and refuse to pay their taxes as a gesture of protest. 

    "Civil Disobedience" received little notice at the time it was written but enjoyed a revival in the 20th century with the self-determination movement of Mahatma Gandhi and the Civil Rights Movement of Martin Luther King, Jr.

  • Ralph Waldo Emerson

    Ralph Waldo Emerson (1803–1882) was a prominent lecturer, poet, and essayist. He was a mentor and friend to Henry David Thoreau. 

    Known as the "Sage of Concord" for his place of residence in Massachusetts, Emerson was a major literary figure and an important spokesman for transcendentalist philosophy, the New England movement that flourished until the Civil War, primarily among intellectuals. Transcendentalism was in part a reaction against Unitarian Church orthodoxy.

    Emerson proved prophetic when he wrote that America's swallowing up of over half of Mexico would be analogous to a man who swallows arsenic, "which brings him down in turn. Mexico will poison us." 

    He was openly against the war and thought that the spectacle of it all had sucked the country into a dangerous state of delirium.

  • John Quincy Adams

    John Quincy Adams (1767–1848) was the eldest son of President John Adams, and himself the sixth President of the United States. 

    The younger Adams gained a national reputation during his tenure as secretary of state (1817–1825) under James Monroe, when he was the central force behind Monroe's foreign policy statement calling for an end to European intervention in the Americas (later known as the Monroe Doctrine). 

    Adams' election to the presidency in 1824 was decided in the House of Representatives because no candidate received a clear electoral majority—the selection of Adams over Andrew Jackson, who won more popular votes, was extremely controversial. After Jackson won a resounding victory in 1828, Adams returned to Congress to serve with distinction as a U.S. representative from the Whig Party (1831–1848). He remains the only former president to serve in the House after his term was over.

    Adams became increasingly outspoken and progressive during the final years of his life as a U.S. representative. At the end of 1844, he finally brought an end to the House "gag rule," which banned all debate about slavery. The rule had been in place for eight years, and Adams had been voted down in each of several previous attempts to repeal it. Adams also led the small Whig opposition to the Mexican-American War. Most Whigs dared not vote against the requisition bills for the war, as doing so would deny resources to Gen. Taylor's army, which was already suffering casualties against Mexican forces. The final vote on the war in the House was 174 to 14. 

    Adams led the tiny opposition and referred to the conflict with Mexico as "a most unrighteous war."

  • Ulysses S. Grant

    Ulysses S. Grant (1822–1885) served as Commander in Chief of the Union Army during the Civil War, leading the North to victory over the Confederacy. Grant later became the 18th President of the United States, serving from 1869 to 1877. 

    After fighting in the Mexican-American War, Grant left the army, only to rejoin at the outbreak of the Civil War. His victories at Fort Henry, Fort Donelson, Vicksburg, and Chattanooga convinced Lincoln to promote him to head all Union Armies. After a bloody campaign in Virginia, Grant accepted Confederate General Robert E. Lee's surrender on April 9th, 1865. Grant's subsequent presidency was mired in corruption, and he became caught up in several political scandals.

    At the time of the Mexican-American War, Grant was just a junior officer. Years later, he reflected back on the war as "one of the most unjust [...] ever waged by a stronger nation against a weaker nation," an act more reminiscent of "European monarchies" than a democratic republic.

    Grant served in one of the two infantry regiments removed to the western border of Louisiana in May 1844. He wrote that though they were never explicitly told so, they all knew that they were there because of the "prospective annexation of Texas." Technically, the forces were "to prevent filibustering (an armed expedition of Americans) into Texas," but Grant thought it was "really as a menace to Mexico in case she appeared to contemplate war." Although Grant claimed that the other officers "were indifferent whether the annexation was consummated or not," Grant himself "was bitterly opposed to the measure."

  • Antonio López de Santa Anna

    General Antonio López de Santa Anna (1794–1876) was a Mexican president and general who capitalized on the upheavals of post-independence Mexico by siding with whatever the dominant faction happened to be at any given time. 

    He led the revolution against Mexico's Emperor Agustín I in 1823, aided Vicente Guerrero before revolting against him, and then helped Anastasio Bustamante to power, only to turn against him. Santa Anna was elected to the presidency of Mexico once (in 1833, followed by his own establishment of reactionary dictatorship in 1834) and held a military dictatorship three other times (1841–1844, 1846–1847, and 1853–1855).

    Santa Anna appeared at the center of several pivotal 19th-century events involving Texas and American plans for western expansion. In 1836, he went to Texas to crush the rebellious U.S. settlers there, and quickly gained infamy in the states for his bloody victory at the Alamo and the massacre he ordered at Goliad. 

    Later that same year, at San Jacinto, Texan Sam Houston defeated Santa Anna's forces and captured the general, forcing him to sign a peace treaty granting Texas its independence. In 1843, Santa Anna threatened war with the U.S. if Texas was annexed into the Union. When war did break out in 1846, the then-exiled Santa Anna returned to Mexico and took command of a Mexican army. 

    At Buena Vista, however, Jefferson Davis' reserve forces stalled Santa Anna's Mexican soldiers. Gen. Zachary Taylor counterattacked, and the Mexicans suffered terrible casualties. Santa Anna's men were then was routed by U.S. forces under General Winfield Scott when they invaded the capital city in September 1847. This invasion created chaos in Mexico, and Santa Anna resigned as president, leaving the government teetering on collapse.

  • Henry Clay

    Henry Clay (1777–1852), who has been called the "Great Pacificator" and the "Great Compromiser," was a U.S. congressman, senator, statesman, and a twice-unsuccessful presidential candidate from the Whig Party (in 1832 and 1844).

    In 1844, Clay lost by the slimmest of margins in his presidential campaign against James Polk. Clay suffered especially for his party's lack of any coherent position on the Texas annexation controversy. In two published letters, Clay opposed the annexation of Texas because, he argued, it posed a danger to the "integrity of the Union." 

    Having ushered Congress through the Missouri Compromise and the nullification crisis, Clay was all too aware of the potentially divisive effects that controversies over slavery could have if reintroduced on the national stage. So, the Whig party platform in 1844 didn't reference Texas at all, until Clay attempted to readjust his position in the "Alabama letters," in which he said he would support annexation if it could be accomplished with the common consent of the Union and without war. He was attempting to satisfy the pro-annexation, proslavery electorate in the South without losing his Northern supporters. 

    The effort failed—his support in New York suffered from this change of position. After the election, Clay went on to oppose war with Mexico, but he voted for war resolutions after the fighting began. Clay wanted to run for the presidency again in 1848, but instead, the Whigs nominated popular war hero Zachary Taylor.