James K. Polk presided over the acquisition of more territory than any other president in American history. During his one-term administration the country expanded by two-thirds with the annexation of Texas, the settlement of the Oregon boundary, and the seizure of all Mexican provinces north of 310. Having been elected in 1844 on a platform demanding Oregon to a northern boundary of 540 40' and Texas to a southern boundary of the Rio Grande River, Polk compromised with Britain on 490 but went to war against Mexico for Texas—with California and New Mexico thrown in for good measure. And thereby hung a tale of sectional conflict that erupted into civil war a decade and a half later.1
"Mr. Polk's War" evoked opposition from Whigs in Congress, who voted against the resolution affirming a state of war with Mexico in May 1846. After the Democratic majority passed this resolution, however, most Whigs supported appropriations for the armies confronting enemy forces. Having witnessed the disappearance of the Federalist party after it opposed the War of 1812, a Whig congressman said sardonically that he now favored "war, pestilence, and famine." Nevertheless, Whigs continued to accuse Polk of having provoked the conflict by sending
1. Polk's motives and actions are laid out in detail by Charles G. Sellers, James K.
Polk, Continentalist 1843-1846 (Princeton, 1966).
American troops into territory claimed by Mexico. They sniped at the administration's conduct of the war and opposed territorial acquisition as a result of it. Encouraged by the elections of 1846 and 1847, in which they picked up 38 seats and gained control of the House, Whigs intensified their attacks on Polk. One of these new Whig congressmen, a lanky, craggy Illinoisian with gray eyes, disheveled black hair, and ill-fitting clothes introduced resolutions calling for information about the exact spot where Mexicans had shed American blood to start the war. Though the House tabled Abraham Lincoln's resolutions, it did pass one sponsored by another Whig declaring that the war had been "unnecessarily and unconstitutionally begun by the President."2
Like the war, Manifest Destiny was mainly a Democratic doctrine. Since the day when Thomas Jefferson overcame Federalist opposition to the purchase of Louisiana, Democrats had pressed for the expansion of American institutions across the whole of North America whether the residents—Indians, Spaniards, Mexicans, Canadians—wanted them or not. When God crowned American arms with success in the Revolution, vouchsafed a Democratic congressman in 1845, He had not "designed that the original States should be the only abode of liberty on earth. On the contrary, He only designed them as the great center from which civilization, religion, and liberty should radiate and radiate until the whole continent shall bask in their blessing." "Yes, more, more, more!" echoed John L. O'Sullivan, inventor of the phrase Manifest Destiny. "More . . . till our national destiny is fulfilled and ... the whole boundless continent is ours."3
Whigs were not averse to extending the blessings of American liberty, even to Mexicans and Indians. But they looked askance at doing so by force. Befitting the evangelical origins of much Whig ideology, they placed their faith in mission more than in annexation. " 'As a city set upon a hill,' " the United States should inculcate the ideas of "true republicanism" by example rather than conquest, insisted many Whigs.
2. CG, 30 Cong., 1 Sess., 64, 95, and Appendix, 93-95. The best study of opposition to the war is John H. Schroeder, Mr. Polk's War: American Opposition and Dissent, 1846-1848 (Madison, 1973). But see also Robert W. Johannsen, To the Halls of the Montezumas: The War with Mexico in the American Imagination (New York, 1985), which shows how popular the war was with the public outside of New England and a few other areas along the Atlantic seaboard.
3. John Wentworth of Illinois and O'Sullivan quoted in Frederick Merk, Manifest Destiny and Mission in American History: A Reinterpretation (New York, 1963), 28, 52-
Although it would "be a gain to mankind if we could spread over Mexico the Idea of America—that all men are bom free and equal in rights," said antislavery clergyman Theodore Parker in 1846, "we must first make real those ideas at home." While the Democratic notion of progress envisioned the spread of existing institutions over space, the Whig idea envisaged the improvement of those institutions over time. "Opposed to the instinct of boundless acquisition stands that of Internal Improvement," said Horace Greeley. "A nation cannot simultaneously devote its energies to the absorption of others' territories and the improvement of its own."4
Acquisition of Mexican territory was Polk's principal war aim. The desire of American settlers in Oregon and California for annexation to the United States had precipitated the dual crises with Britain and Mexico in 1846. Praising these emigrants as "already engaged in establishing the blessings of self-government in the valleys of which the rivers flow to the Pacific," Polk had pledged to extend American law to "the distant regions which they have selected for their homes."5 A treaty with Britain secured Oregon north to the 49th parallel. But efforts to persuade Mexico to sell California and New Mexico had failed. So Polk decided to use force. Soon after becoming president he ordered the Pacific fleet to stand ready to seize California's ports in the event of war with Mexico. In the fall of 1845 Polk instructed the U.S. consul at Monterey to encourage annexation sentiment among American settlers and disaffected Mexicans.
Americans in California needed little encouragement, especially when they had among them a glory-hunting captain of the army topographical corps, John C. Fremont. Famous for his explorations of the West, Fremont was also the son-in-law of Missouri's powerful Senator Thomas Hart Benton. When rumors of war with Mexico reached the Sacramento valley, Fremont took it upon himself to assist settlers in an uprising that proclaimed an independent California. This "bear flag republic" (its flag bore the image of a grizzly bear) enjoyed a brief existence before its citizens celebrated official news of the war that ensured their annexation by the United States.
4. Schroeder, Mr. Polk's War, 75-76; Parker, "A Sermon of War," in Robert E. Collins, ed., Theodore Parker: American Transcendentalist (Metuchen, N.J., 1973), 252;
Greeley quoted in Daniel Walker Howe, The Political Culture of the American Whigs
While these proceedings unfolded, Missouri volunteers and a regiment of regulars were marching over the Santa Fe trail to seize the capital of New Mexico. Commanded by Stephen Watts Kearny, these tough dragoons occupied Santa Fe on August 18, 1846, without firing a shot. After raising the American flag, Kearny left behind a garrison and pushed across the desert to California with a hundred men who joined a few hundred sailors, marines, and volunteers to subdue Mexican resistance there by January 1847. During the next several months a string of stunning American victories south of the Rio Grande culminating in the capture of Mexico City ensured the permanence of these American conquests. The only remaining question was how much territory to take.
Polk's appetite was originally sated by New Mexico and California. In April 1847 he sent Nicholas Trist to Mexico as a commissioner to negotiate a treaty for these provinces. But the ease of American conquest made Polk suddenly hungry for more territory. By the fall of 1847 a Democratic movement to annex "all Mexico"—or at least several additional provinces—was in full cry. The whipsaw cuts and rasps of allMexico Democrats and no-territory Whigs left Trist on a precarious limb three thousand miles away in Mexico City where the proud Santa Anna proved reluctant to yield up half his country. Polk sided with the hard-liners in Washington and recalled Trist in October 1847. But a breakthrough in negotiations appeared possible just as Trist received the recall dispatch, so he disobeyed orders and signed a treaty that fulfilled Polk's original instructions. In return for a payment by the United States of $15 million plus the assumption of Mexican debts to American citizens, Mexico recognized the Rio Grande boundary of Texas and ceded New Mexico and upper California to the United States.6 When this Treaty of Guadalupe Hidalgo reached Washington in February 1848, Polk initially spurned it. On second thought, however, he submitted it to the Senate, where the Whigs would have enough votes to defeat any treaty that sliced off more Mexican territory but might approve one that avoided the appearance of conquest by paying Mexico for California and New Mexico. The strategy worked; the Senate ratified the treaty by a vote of 38-14, with five of the opposition votes coming from Democrats
6. This cession included the present states of California, Nevada, and Utah, most of
New Mexico and Arizona, and parts of Oklahoma, Colorado, and Wyoming as well as one-third of Texas.
who wanted more territory and seven from Whigs who wanted none.7 This triumph of Manifest Destiny may have reminded some Americans of Ralph Waldo Emerson's prophecy that "the United States will conquer Mexico, but it will be as the man swallows the arsenic, which brings him down in turn. Mexico will poison us."8 He was right. The poison was slavery. Jefferson's Empire for Liberty had become mostly an empire for slavery. Territorial acquisitions since the Revolution had added the slave states of Louisiana, Missouri, Arkansas, Florida, and Texas to the republic, while only Iowa, just admitted in 1846, had increased the ranks of free states. Many northerners feared a similar future for this new southwestern empire. They condemned the war as part of a "slave power conspiracy" to expand the peculiar institution. Was not President Polk a slaveholder? Had he not been elected on a platform of enlarging slave territory by annexing Texas? Were not pro-slavery southerners among the most aggressive proponents of Manifest Destiny? Did not most of the territory (including Texas) wrested from Mexico lie south of the old Missouri Compromise line of 36° 30'—a traditional demarcation between freedom and slavery? The Massachusetts legislature indicted this "unconstitutional" war with its "triple object of extending slavery, of strengthening the slave power, and of obtaining control of the free states." James Russell Lowell's rustic Yankee philosopher Hosea Biglow fretted that
They just want this Californy
So's to lug new slave-states in To abuse ye, an' to scorn ye, An' to plunder ye like sin.9
Polk could not understand what the fuss was about. "In connection with the Mexican War," he wrote in his diary, slavery was "an abstract question. There is no probability that any territory will ever be acquired from Mexico in which slavery would ever exist." Agitation was thus "not only mischievous but wicked." But a good many congressmen—
7. Senate Executive Docs., 30 Cong., 1 Sess., no. 52, p. 36. The other two opposition votes came from Democrats who disliked the treaty for other reasons.
8. Edward W. Emerson and Waldo E. Forbes, eds., Journals of Ralph Waldo Emerson, 10 vols. (Boston, 1909-14), VII, 206.
9. H. V. Ames, ed., State Documents on Federal Relations (Philadelphia, 1906), 24142; The Works of James Russell Lowell, Standard Library ed., 11 vols. (Boston, 1890), VIII, 46-47.
even some in Polk's own party—did not share the president's conviction. They believed agitation of the question necessary. This issue overshadowed all others from 1846 to 1850. Hundreds of congressmen felt moved to speak on the matter. Some of them agreed with Polk that it was an "abstract" issue because "natural conditions" would exclude slavery from these lands. "The right to carry slaves to New Mexico or California is no very great matter," said John J. Crittenden of Kentucky, because "no sensible man would carry his slaves there if he could."10 But numerous southerners disagreed. They noted that cotton was already grown in river valleys of New Mexico. Slaves had labored in mines for centuries and would prove ideal mineworkers in these territories. "California is peculiarly adapted for slave labor," resolved a southern convention. "The right to have [slave] property protected in the territory is not a mere abstraction." A Georgia newspaper heightened abolitionist suspicions of a slave-power conspiracy by professing a broader purpose in opening these territories to slavery: it would "secure to the South the balance of power in the Confederacy, and, for all coming time . . . give to her the control in the operations of the Government."11
Of the congressmen who spoke on this matter, more than half expressed confidence (if southern) or fear (if northern) that slavery would go into the new territories if allowed to do so.12 Many of them conceded that the institution was unlikely to put down deep roots in a region presumed to be covered with deserts and mountains. But to make sure, northern congressmen voted for a resolution to exclude slavery therefrom. This was the fateful Wilmot Proviso. As Congress neared adjournment on the sultry Saturday night of August 8, 1846, Pennsylvania's first-term Representative David Wilmot rose during the debate on an appropriations bill for the Mexican War and moved an amendment: "that, as an express and fundamental condition of the acquisition of any territory from the Republic of Mexico . . . neither slavery nor involuntary servitude shall ever exist in any part of said territory."13
10. Milo Milton Quaife, ed., The Diary of James K. Polk during His Presidency, 1845
to 1849, 4 vols. (Chicago, 1910), II, 308; Michael F. Holt, The Political Crisis of the 1850s (New York, 1978), 77.
11. Robert S. Starobin, Industrial Slavery in the Old South (New York, 1970), 18-20; Milledgeville Federal Union, Nov. 10, 1846, quoted in Schroeder, Mr. Polk's War,
Was this article helpful?