Editor’s note: This is the 40th in a series of essays on the history and meaning of the American political tradition.
The course of this nation’s expansion was brought almost to completion by conquest during the presidency of James K. Polk, a protégé of Andrew Jackson, who favored Jackson’s expansionist policies and followed them to the letter. He was known as “young hickory,” a chip off the old block. Polk presided over the U.S.-Mexican War (1846–48). Henry Clay, whom Polk defeated in the Presidential election of 1844, judged that Polk incited it, and there is general agreement that he did just that.
The event that provoked it was the annexation of the Republic of Texas in 1845. Mexico won its independence from Spain in 1824, after its own war of revolution. Texas was then a province of the Mexican Republic. It was sparsely populated, and the Mexican government encouraged immigrants from the United States (Anglos who became known as Texians); before long Texians outnumbered Mexicans by a ratio of four to one. They soon came into conflict with the Mexican government led by Antonio Lopez de Santa Anna, an autocrat with imperial ambitions. In 1835–36, Texas declared its independence and engaged in war with Mexico. In the battle of San Jacinto, a Texian army under command of General Sam Houston defeated a Mexican army, led by Santa Anna. The victory was decisive, and Texas won its independence, but it was only virtual, for the government of Mexico did not recognize Texas as a nation.
In 1843, the Republic of Texas sought admission to the United States. President Tyler instructed his Secretary of State to enter into negotiations with Texas, and an agreement was concluded in secret. This soon became public, and statehood for Texas became an issue during the presidential campaign of 1844. Henry Clay, the Whig candidate, opposed it; the Democratic candidate, James Polk, favored it. His justification for admission of Texas was “manifest destiny,” which was the central theme of his presidential campaign and of his presidency; after his election he pursued it with zeal and cunning. Texas was admitted to the Union Dec. 29, 1845.
Even after the annexation of Texas, its southwestern border remained in dispute; the Mexican government claimed it was the Neuces River, the United States claimed it was the Rio Grande, which ran south and west of the Neuces. In February 1846, President Polk ordered General Zachary Taylor to advance with his army south of the Neuces and proceed toward the Rio Grande. Taylor obeyed, and took up a position just north of the Rio Grande, opposite the Mexican city of Matamoras. Mexico responded to this provocation by sending a detachment of cavalry across the Rio Grande where they met and defeated a squadron of American dragoons; those who survived surrendered and became prisoners of war.
News of the American defeat was slow to arrive in Washington. On May 9, even before receiving it, Polk proposed to his cabinet that the United States declare war on Mexico; a message was sent to Congress, and on May 13, 1846, war was declared.
Militarily, the war was a great success. U.S. forces under Zachary Taylor, Winfield Scott, John C. Fremont, Commodore Perry and others were victorious. It was a short, savage war, but the savagery was not only between opposing armies, but also against Mexican civilians. In a report to the Secretary of War, General Scott complained of the savagery of his own troops toward the Mexican people: “Our militia & volunteers, if a tenth of what is said be true, have committed atrocities, horrors in Mexico, sufficient to make Heaven weep & every American … blush for his country. Murder, Robbery, Rape of mothers & daughters, in the presence of tied up males.” It was not a good war. It was not a just war. It was an imperial war of conquest. It is no wonder that we have grown forgetful of it.
The consequence of the war was the dismemberment of Mexico. In accordance with the Treaty Guadalupe Hidalgo, concluded in May 1848, Mexico ceded half of its territory to the United States, comprising what is now all or parts of the states of Arizona, California, Colorado, Kansas, New Mexico, Nevada, Texas, Utah and Wyoming. The United States paid Mexico $15 million — at present day values, $450 million, a 30-fold increase, but still a bargain.
One feature of the U.S.-Mexican War that gives it prominence is its pervasive racism; it was epidemic among the American volunteers and of their leaders as well. It infected the minds of statesmen who presided over the war, including those who believed it to be unjust. The celebrated American statesman Henry Clay opposed the war and lost a presidential election because of it. He also lost a son: Henry Clay Jr. was killed in the Battle of Buena Vista.
In November 1847, when the war was near its end, Clay delivered a speech concerning its aftermath. He opposed the advocates of Manifest Destiny who were calling for the annexation of the whole of Mexico. He warned that this would be a grave mistake. “We ought not to forget the warning voice of history, which teaches the difficulty of combining and consolidating together conquering and conquered nations.” Mexico would have to be pacified; it would require an army of occupation to accomplish this; there would be constant resistance and continuing bloodshed and no peace.
He cited differences of race and religion as the root of the problem, and compared the conquest of Mexico to the English conquest of Ireland. He noted that the Irish and Mexicans are Celtic and Roman Catholic; the English and Americans are Saxon and Protestant. It would be like mixing oil and water. Besides, the United States has sufficient territory in which to grow. Hence, the United States should leave Mexico to the Mexicans and go west. And so it did, and this racial prejudice went with it; it continues today; it inhabits the White House and inspires its policies.
President Polk further facilitated Western expansion by negotiating a treaty with Great Britain in 1846 acquiring the Oregon Territory, thus completing the expansion of the Pacific Northwest. From the point of view of Manifest Destiny, one might expect that he would be regarded as a great President. That did not happen, although as one historian has noted, Polk “worked himself to death” to fulfill this myth. He died shortly after leaving office. Perhaps he felt shame for the suffering he caused. If he did there is no record of it. The shame is ours.
Postscript — A message from the author to his readers: This essay, the 40th in the series, concludes Part One of my effort to trace the history of the American Political Tradition. Part Two will run from the Civil War through the New Deal. In order to prepare for it, I will take a break. Part Two will resume after the New Year. Thank you for reading.