The Missouri Compromise of 1820

by Matthew Mason

The Missouri Compromise settled the question of slavery in that state but was a harbinger of issues arising as new states were admitted to the Union thereafter.

The Missouri debates of 1819-1821 served as a significant pivot in the United States’ sectional controversy over slavery. The months-long dispute over restricting slavery in the new state was at the same time the culmination of previous debates, an intense debate in itself that refined many previous arguments, and a harbinger of coming events. Settled formally by two compromises, the issues this crisis raised festered throughout the 1820s and were a crucial signpost on what later became clear was the road to the Civil War.

When the Missouri Territory applied for statehood in February 1819, an amendment to the statehood bill offered by Congressman James Tallmadge Jr. of New York commenced the first round of the controversy, which lasted until February 1820. The Tallmadge Amendment would have halted the importation of slaves into Missouri and gradually liberated those already in bondage there. This phase of the crisis passed with the first Missouri Compromise, which authorized Missouri to join the Union without a restriction on slavery, but also admitted the free state of Maine to the Union. It also drew a line through the rest of the Louisiana Purchase territories at Missouri’s southern border, restricting slavery north of that line but allowing it below. The proposed admission of Missouri to the Union authorized its inhabitants to draft a state constitution and Missourians started the second round of the crisis with a draft constitution guaranteeing slavery and barring free people of color from entering their state. In late 1820 and early 1821, Congress and the nation debated the acceptability of the Missouri state constitution. Another congressional compromise ended the second round, and a presidential proclamation in August 1821 recognized Missouri’s admission with no comment on the controversial clauses.

Though ending in compromises, these debates sent shock waves throughout American politics both at the time and in subsequent years. At the height of the first round, Speaker of the House Henry Clay observed that the Missouri question “monopolizes all our conversation, all our thoughts and . . . all our time. No body seems to think or care about any thing else.” But as newspaper columns, mass meetings, and even mob actions both North and South testified, the debate consumed more than Congress. As Richmond newspaper editor Thomas Ritchie put it, “the whole country appears agitated by this question.” Indeed, it was precisely because their constituents were so absorbed in the conflict that Congressmen felt the need to go endlessly on record on the question even without hope of swaying their fellow legislators.[1]

Such deep-seated convictions about the extension of slavery to Missouri did not spring up out of nowhere. Indeed, voters and politicians in both North and South brought to the Missouri debates baggage from previous political combat involving slavery. The intensity and particular form of the debate caught very few alert observers by surprise. Many Northerners’ baggage included real and recent anxieties about slavery’s infringements on their liberties. The foreign policies of the Southern-friendly Jefferson and Madison administrations — including an Embargo on foreign trade that crippled New England’s mercantile economy and the War of 1812 that violated many Yankees’ moral principles as well as their pocketbooks — had convinced many New Englanders that the Federalists were right to grouse about the power of slaveholders in the federal government. The partisan-cum-sectional drive against these policies culminated in the Hartford Convention of 1814-1815, whose recommended amendments to the Constitution included the repeal of the clause that counted three-fifths of all slaves towards a state’s weight in the House of Representatives and Electoral College.

For all this history in New England, however, it was no coincidence that the Tallmadge Amendment came from a New Yorker, or that the Mid-Atlantic States provided its firmest base of support. In the years immediately following the War of 1812, when the Southern and Mid-Atlantic wings of the dominant Democratic-Republican Party quarreled over economic policy, dissidents in the Mid-Atlantic revived Federalists’ sectional rhetoric for the slaveholders in charge in Washington. Even more significantly, slavery itself very visibly reached its hand into the Mid-Atlantic’s proudly free states in the postwar years. As demand for slave labor in the expanding Southern plantation complex increased, the sale of term slaves — slaves awaiting their freedom under the provisions of Northern states’ gradual emancipation laws — from states like New York, New Jersey, and Pennsylvania to the Deep South drew the outraged attention of both legislators and citizens. So did the rising practice of kidnapping free African Americans from the North into Southern slavery. A newspaper writer’s response to one particularly violent kidnapping spoke to how such practices affronted Mid-Atlantic whites’ pride in residing in the free states. “Fellow citizens,” he cried, “these outrages were committed upon a family of free people in Philadelphia, and on the Sabbath day.”[2]

Northwestern states also lined up solidly behind the Tallmadge Amendment, in part because of Missouri’s location. If kidnapping and the slave trade threatened Northerners’ desired distance from slavery in the Mid-Atlantic, many Northwesterners worried that slavery itself would spread into their region. The antislavery residents of Illinois had barely fended off an attempt to legalize slavery in their state as recently as 1818, which provided vital context for why Northwesterners were so alarmed at the prospect of planting slavery in Missouri. In particular, the South’s position that states possessed unlimited sovereignty over slavery seemed calculated to abet slavery’s transgression of its traditional bounds. Many Northerners realized that these arguments negated the Northwest Ordinance of 1787, which to them was a sacred cow. Given slaveholders’ mania for state sovereignty, Representative Daniel Pope Cook of Illinois doubted whether they would honor the proscription of slavery north of the proposed Missouri Compromise line. “Are we to understand gentlemen as conceding the point,” he queried his colleagues, “that Congress has the power to make that restriction or territorial prohibition perpetual and binding on the States hereafter?” At this William Lowndes of South Carolina “smiled and shook his head, whereupon Cook exclaimed, “Away with your compromise. Let Missouri in, and the predominance of slave influence is settled, and the whole country will be overrun with it.”[3]

This immediate context is a key to understanding why a controversy exploded over Missouri in 1819-1821 and not to the same degree over previous expansions of slave territory and admission of slave states. This was in part because Missouri lay too far north to enter quietly as a slave state. Slavery seemed less necessary and more threatening to bordering free states in Missouri than in the Deep South. Furthermore, as John Craig Hammond has shown, before the War of 1812 many Northerners were more concerned about all western territories’ loyalty to the Union than about the very real North-South divide. Furthermore, the national government’s effective authority in the western territories was very thin on the ground before and during the war. These political facts kept many even strongly antislavery Northerners from a desire to press territories and would-be states too hard for unrealistic slavery restrictions. The fact that the Union and the federal government’s power survived the war intact helped encourage increasing numbers of Northerners, in both parties, to get behind the restrictionist drive to assert that power in the name of defending against slavery’s aggressive course.[4]

Furthermore, the radicalizing effects of the Missouri Crisis pushed many Northerners into even less compromising positions than they brought to it. Losing the fight to restrict slavery in Missouri, and Southerners’ bellicose statements during the debates, led many Northerners to vow resistance to any new slave state or territory. And in terms of antislavery argumentation, the Missouri controversy not only produced a compendium of traditional Northern attacks on slavery and slaveholders, but it also led some restrictionists to take up some novel and advanced antislavery positions. Senator Rufus King of New York made the best-known of many such rhetorical sorties against slavery. In a speech on the Senate floor, King asserted that he had “yet to learn that one man can make a slave of another. If one man cannot do so, no number of individuals can have any better right to do it.” He therefore maintained that “all laws or compacts imposing any such condition upon any human being, are absolutely void, because contrary to the law of nature, which is the law of God,” and which “is paramount to all human control.” King later repudiated some of the radical implications of this statement for slavery beyond Missouri, but it was evidence of how far the debates had pushed some Northerners. Part of that pushing came from Southern debaters who probed the inconsistency between the Tallmadge Amendment’s gradualist approach and the high-flying antislavery principles that Northerners professed.[5]

In like manner this extended and vociferous treatment of the problem of slavery in the United States pushed some Southern representatives to more extreme proslavery positions. White Southerners perceived the debate itself as a threat to their peculiar institution. This was less a revelation to many slaveholders than a confirmation of existing suspicions or convictions, and accordingly it intensified trends already underway in their thought and tactics. The Northern attempt to use the federal government to halt the spread of slavery accelerated a Southern movement to embrace state rights and strict construction of the Constitution. It convinced many Southerners to emphasize the Constitution, narrowly construed, at the expense of the Declaration of Independence and the liberal principles it enshrined. But if the slaveholders posted their own anthology of extant defensive doctrines in response to the North’s voluminous collection, they also moved toward a fuller defense of Southern bondage.

As Northerners exposed the flaws of older defenses of slavery in the Missouri debates, some Southerners argued for the first time on a national stage that slavery was a positive good. For decades Southerners had apologized for slavery as a necessary evil; but when they advocated spreading it by accepting it in Missouri, Northerners cried foul. One of the great evils of slavery was that “taking it away does not remove it,” pointed out one Northern editor. “The spread of our negro population, is like the spread of a plague; it will afford no relief to impart the malady to others: we may give the infection to the whole world and the virulence of our own disease will be unabated.” In the face of such rebukes, John Randolph of Virginia groused that “these Yankees have almost reconciled me to negro slavery.” Senator William Smith of South Carolina delivered the strongest proslavery speech of the whole Missouri controversy, in response to Northerners whom he accused of fomenting servile rebellion in the South. “This people are so domesticated,” he submitted, “or so kindly treated by their masters, and their situations so improved,” that ill-disposed Yankees “cannot excite one among twenty to insurrection.” Smith’s whole speech was an unmitigated tribute to the virtues of slavery. Yankees recoiled at such principled and unapologetic defenses of slavery, but it was their own assault on the slaveholders’ previous defenses that had elicited the new ones.[6]

But for all this, the center held, at least enough to reach a compromise in 1820 and usher Missouri into the Union in 1821. A coalition of moderate Northerners and Southerners was able to come together to achieve compromise. Once they voted for compromise, especially the Northerners took an enormous amount of abuse from their constituents and political enemies. Indeed, it was during the Missouri Crisis that those enemies applied the term “doughfaces” first to Northern politicians who favored compromise with the South. In response, these moderates did as they had always done, in appealing to the priority of Union over their particular stance on slavery. Preserving the Union and the sovereignty of states like Missouri, they pled, were the true issues at stake here — not the increase of slavery in the United States. They thus advanced and refined arguments that had been used by sectional moderates in previous sectional struggles such as during the War of 1812.

But it was more than arguments that held the anti-restrictionist coalition together. As historian Robert Forbes has shown, the Monroe administration and Congressional leaders leveraged some Northerners’ competing local concerns to get them to vote against the restriction. “Specific circumstances in each state,” as Forbes has written, encouraged cooperation with the anti-restrictionists. In Massachusetts it might be raising the specter of the Federalists returning to power if the restriction prevailed. In Pennsylvania it might be horse trading of a more tangible kind, tying the passage of a tariff that would protect that state’s burgeoning manufacturing industry to passage of the compromise. And so forth.[7]

Nowhere was that pressure stronger than in Maine, whose long drive for separation from Massachusetts stood in jeopardy when Congressional leaders linked Maine statehood with Missouri statehood. If doughfaces were on the defensive in other states, this move put Maine restrictionists in a bind. What did the compromise’s engineers “virtually say to the members from Maine?” yelped Maine restrictionists in an open letter. “Was it not this? You desire the admission of Maine – you are under the strongest necessity of obtaining it – we have no objection to it – you ought to have it; but you shall not have it,” unless you vote against the restriction on Missouri, “whatever may be your sentiments, or however abhorrent it may be to your notions of the rights of man and of humanity.” They urged Northern unity, but also noted nervously that they hoped “that the good sense of the people of Maine will enable them to discriminate between measures calculated to promote our great national interests, and those tending alone to secure power and influence in any particular portion of our country.” Normally, it was doughfaces who defensively portrayed themselves as pursuing the interests of the whole Union rather than local or sectional ones. But Congressional legerdemain, among other effects, had placed Maine’s doughfaces in an unusual position of strength.[8]

But for all the importance of the compromises that terminated both active rounds of the Missouri crisis, that sustained conflict had ushered in a new clarity in the sectional politics of the United States and moved each section toward greater coherence on the slavery issue. In the immediate future, the legacy of Missouri hung heavily over all partisan and sectional politics throughout the 1820s. What John Quincy Adams observed relative to presidential politics was true well beyond that sphere as well: “The Missouri question,” he mused, “is indeed a flaming sword that waves round on all sides and cuts in every direction.” As Donald Ratcliffe has argued in a bracing recent revision of the standard picture, the turbulent 1820s — not the 1830s — actually represented the height of antislavery’s influence on national politics. But whether for the 1820s, the 1830s, or beyond, the Missouri Crisis pointed to new directions in the antebellum era. With every new controversy sectional polarization followed patterns that would be familiar to the Missouri combatants. And while moderates in both sections were not helpless in the face of the divide over slavery, recurring iterations of the Missouri crisis would stretch their resources and arguments to the limit.[9]

  • [1] Henry Clay to John J. Crittenden, 29 January 1820, in Glover Moore, The Missouri Controversy (Lexington: University of Kentucky Press, 1953), 90; Richmond Enquirer, January 22, 1820.
  • [2] Philadelphia Aurora, July 3, 1818.
  • [3] The Northwest Ordinance of 1787 established the basis of settlement of the first organized territory in the United States, an area north of the Ohio River running west of the Mississippi and South of the Great Lakes. Eventually the states of Ohio, Indiana, Illinois, Michigan, Wisconsin and part of Minnesota would be formed from this territory.  Article VI of the Ordinance banned the future importation of slaves into these territories. The Ordinance therefore helped established the Ohio River as the boundary between free and slave states; 35 Annals of Cong. 1111 (1820).  This exchange foretold the repeal of the Missouri Compromise in the Kansas-Nebraska Act.
  • [4] John Craig Hammond, Slavery, Freedom, and Expansion in the Early American West (Charlottesville: University of Virginia Press, 2007).
  • [5]35 Annals of Cong. 380-81 (1820).  
  • [6] Boston Columbian Centinel,  December 8, 1819; John Randolph to Dr. John Brockenbrough,  February 24, 1820, in Norman K. Risjord, The Old Republicans: Southern Conservatism in the Age of Jefferson (New York and London: Columbia University Press, 1965), 215-16; 35 Annals of Cong. 259-75 (1821), quotations on 267. 
  • [7] Robert Pierce Forbes, Chap. 3 in The Missouri Compromise and Its Aftermath: Slavery and the Meaning of America (Chapel Hill: University of North Carolina Press, 2007), quotation on 70.
  • [8] Address to the People of Maine (Washington, D.C.: Davis & Force, 1820), 3-14.  For a fuller exploration of this angle on the Missouri Crisis, see Matthew Mason, “The Maine and Missouri Crisis: Competing Priorities and Northern Slavery Politics in the Early Republic,” Journal of the Early Republic, forthcoming.
  • [9] Charles Francis Adams, ed., Memoirs of John Quincy Adams, Comprising Portions of His Diary from 1795 to 1848 (Philadelphia: J.B. Lippincott 1874-1877), (Freeport, NY: Books for Libraries Press, 1969), 5:91; Donald J. Ratcliffe, “The Decline of Antislavery Politics, 1815-1840,” in John Craig Hammond and Matthew Mason, eds., Contesting Slavery: The Politics of Bondage and Freedom in the New American Nation (Charlottesville: University of Virginia Press, 2011), 267-90.  

If you can read only one book:

Mason, Matthew. Slavery and Politics in the Early American Republic. Chapel Hill: University of North Carolina Press, 2006.


  • Adams, Charles Francis, Memoirs of John Quincy Adams, Comprising Portions of His Diary from 1795 to 1848. 12 vols. Philadelphia, J.B. Lippincott, 1874-1877.

  • Ashworth, John. Slavery, Capitalism, and Politics in the Antebellum Republic, Vol. 1, Commerce and Compromise, 1820-1850. Cambridge, U.K.: Cambridge University Press, 1995.

  • Forbes, Robert Pierce. The Missouri Compromise and Its Aftermath: Slavery and the Meaning of America. Chapel Hill: University of North Carolina Press, 2007.

  • Ford, Lacy K. Deliver Us From Evil: The Slavery Question in the Old South. Oxford, U.K.: Oxford University Press, 2009.

  • Hammond, John Craig. Slavery, Freedom, and Expansion in the Early American West. Charlottesville: University of Virginia Press, 2007.

  • Hammond, John Craig and Matthew Mason, eds. Contesting Slavery: The Politics of Bondage and Freedom in the New American Nation. Charlottesville: University of Virginia Press, 2011.

  • Howe, Daniel Walker. What Hath God Wrought: The Transformation of America, 1815-1848. Oxford, U.K.: Oxford University Press, 2007.

  • Kornblith, Gary J. Slavery and Sectional Strife in the Early American Republic, 1776-1821. Lanham, MD: Rowman & Littlefield, 2010.

  • Moore, Glover. The Missouri Controversy. Lexington: University of Kentucky Press, 1953.

  • Wilentz, Sean. The Rise of American Democracy: Jefferson to Lincoln. New York: W.W. Norton, 2005.


No organizations listed.

Web Resources:

  • A Student’s Guide to the Missouri Compromise provides an overview of the Missouri Compromise and a link to numerous websites containing additional relevant information. This website was identified by Edgar R. of the Compton Community Center.

    Visit Website

Other Sources:

No other sources listed.