Missouri Compromise

• 1. Introduction

  ›

  The Missouri Compromise drew a line across the American map that Thomas Jefferson, in April 1820, called a fire bell in the night. Writing to John Holmes just weeks after President James Monroe signed the legislation, the former president warned that a geographical division coinciding with a moral and political principle, once drawn, would never be obliterated. He was right. The line ran at 36 degrees 30 minutes north latitude, the southern boundary of Missouri, and it promised that slavery would not spread above it through the remaining lands of the Louisiana Purchase. Below it, slavery would be free to expand.

  The 16th United States Congress passed the legislation on the 3rd of March, 1820, and Monroe signed it three days later. It admitted Missouri as a slave state and Maine as a free state, preserving an equal count of eleven free and eleven slave states in the Senate. For more than two decades, the arrangement held. Then it began to unravel, and Jefferson's fire bell rang louder with each passing crisis, until the Kansas-Nebraska Act effectively killed the Compromise in 1854 and the Supreme Court declared it unconstitutional in Dred Scott v. Sandford three years after that.

  How did a nation that declared all men created equal in 1776 arrive at a law that drew a formal boundary around slavery's reach? What made the Senate the pivot point for slaveholding power? And what did five representatives from Maine see that their colleagues refused to acknowledge? Those questions run through the story of this Compromise and through everything that came after it.

• 2. A Powder Keg Waiting

  ›

  James Tallmadge Jr. was 41 years old and a political outsider when he stepped onto the floor of the House of Representatives on the 13th of February, 1819, and, in the words of one account, tossed a bombshell into the Era of Good Feelings. His amendment to Missouri's statehood bill would have prohibited any further introduction of enslaved people into the state and freed all children born to enslaved parents there once they reached 25 years of age. The reaction was swift and ferocious.

  Debates in the House lasted only three days but were described by observers as rancorous, fiery, bitter, blistering, furious, and bloodthirsty. One representative warned that the controversy had kindled a fire which all the waters of the ocean cannot put out, which seas of blood can only extinguish. Another declared that if civil war must come, let it come. These were not abstract threats; they came from men who understood the structural stakes.

  Tallmadge himself had experience with slavery's legal entanglements. He had played a leading role in accelerating emancipation of the remaining slaves in New York in 1817 and had campaigned against Illinois's Black Codes, laws that permitted indentured servitude and a limited form of slavery in a nominally free state. When illness took him off the floor after proposing his amendment, Representative John W. Taylor of New York stepped in. Taylor had proposed a similar restriction for Arkansas Territory just days earlier, in February 1819, and it had been defeated 89-87, a margin thin enough to show how evenly the nation was split.

  The House vote on Tallmadge's provisions broke along almost perfectly sectional lines: 87-76 for prohibiting further slave migration into Missouri, and 82-78 for freeing the children of enslaved parents at age 25. Northern representatives outnumbered southerners 105 to 81 in the House, and those numbers showed. The Senate, however, was a different instrument entirely.

• 3. The Senate as Fortress

  ›

  In the Senate, both halves of the Tallmadge Amendment were rejected. The restriction on new enslaved people entering Missouri lost 22-16, and the gradual emancipation provision lost 31-7. Those margins were not accidents. They reflected a deliberate architecture of southern power built into the Constitution.

  Each state sent two senators regardless of its population, and the South, with a smaller free population than the North, benefited enormously from that arrangement. Since 1815, sectional parity in the Senate had been maintained through paired admissions, admitting one free state alongside each slave state to preserve a balance. By the time Missouri applied, both sections held 11 states each. Admitting Missouri as a slave state without a matching free state would tilt the Senate toward the South, giving slaveholding interests a durable majority in the one chamber where northern population advantages could not reach.

  Senator Jesse B. Thomas of Illinois supplied the mechanism that broke the deadlock. Thomas proposed an amendment banning slavery from all remaining Louisiana Purchase lands north of 36 degrees 30 minutes north latitude, excepting Missouri itself. That provision, attached to a Senate bill linking Maine's admission to Missouri's, gave northern legislators something concrete: a hard geographical limit on slavery's westward expansion. Speaker of the House Henry Clay of Kentucky, who would later earn the title "The Great Compromiser", then did the painstaking work of building a majority in the House. He pressured half of the anti-restrictionist southern representatives to accept the Thomas proviso and maneuvered enough northern restrictionists into supporting Missouri as a slave state. The House approved the Senate compromise amendment 90-87, with all opposition from free-state representatives.

  The Senate vote for the overall compromise was 24-20. The full bill then passed the House 134-42, with most opposition coming from southern states.

• 4. Jefferson's Paradox

  ›

  The deeper conflict underneath the Missouri Crisis was not simply about geography. It was about what the founding generation had promised and what they had instead built. The Declaration of Independence in 1776 had grounded liberty and equality as universal human rights. The Constitution of 1787 had been formed to embody those principles while simultaneously, in the phrase used by one historian, burdened with the one legacy that defied the principles of 1776, namely human bondage.

  Slaveholders had co-operated in authorizing the Northwest Ordinance in 1787 and outlawing the trans-Atlantic slave trade in 1808 on the implicit understanding that slave states would take steps to relinquish the institution as opportunities arose. In the 1790s, that seemed plausible. Southern states after the Revolution had largely regarded slavery as an institution in decline. But from the 1790s, with the cotton gin, to 1815, with soaring international demand for cotton, slave-based agriculture underwent an immense revival that spread westward to the Mississippi River.

  In Missouri, the dynamic was slightly different. The lower Missouri River valley had no prospects as a major cotton producer. The only crop regarded as promising for slave labor was hemp culture. Southern planters had nonetheless immigrated with their enslaved workers, and the slave population rose from 3,101 in 1810 to 10,000 in 1820. Out of a total population of 67,000, slaves represented about 15 percent.

  When slaveholders in the 16th Congress tried to reconcile expansion with their inherited egalitarian rhetoric, some turned to a theory they called diffusion, arguing that spreading slavery geographically would encourage its decline. Northern Democratic-Republicans, citing Jefferson's own Declaration, rejected that logic and held that Congress had both the authority and the obligation to limit slavery's spread on constitutional and moral grounds. Jefferson himself, by then retired, did not publicly champion either position but privately expressed terror at what the compromise line implied for the Union's future.

• 5. Five Voices Against

  ›

  Maine's path to statehood had nothing to do with slavery at the outset. The northern district of Massachusetts wanted independence from a state it no longer shared a border with after the War of 1812. Its petition for statehood was pending in Congress when the Senate, recognizing an opportunity, linked Maine's admission to Missouri's, making one conditional on the other.

  Most of Maine's representatives accepted the arrangement. Five did not. Martin Kinsley, Joshua Cushman, Ezekiel Whitman, Enoch Lincoln, and James Parker voted against the Missouri Compromise and against Maine's own independence in 1820. In a written defense, they warned that if the North embarked upon this compromise and ignored what experience proved, namely that southern slaveholders were determined to dominate the nation through ironclad unity and perpetual pressure to demand more land and more slaves, then Americans, in their words, shall deserve to be considered a besotted and stupid race, fit only to be led blindfold, and worthy only to be treated with sovereign contempt.

  Their prediction tracked closely with what followed. The trend of paired admissions continued after 1820: Arkansas entered as a slave state in 1836, Michigan as a free state in 1837. In 1845, two slave states, Texas and Florida, were admitted, balanced by the free states of Iowa and Wisconsin in 1846 and 1848. The balance held, barely, until the Compromise of 1850, which only briefly defused the tensions that had been building since Missouri. Four more free states would be admitted before the Civil War began, and no more slave states.

  The five Maine dissenters wrote in a moment when the price of Missouri's entry into the Union seemed obvious to anyone willing to look. Their dissent was recorded and lost in the compromise's passage. The Peoria Speech of Abraham Lincoln, delivered on the 16th of October, 1854, in direct response to Stephen Douglas's repeal of the Missouri Compromise through the Kansas-Nebraska Act, echoed many of the same arguments the five Mainers had made three decades earlier.

• 6. A Line That Could Not Hold

  ›

  The Missouri Compromise was widely hailed for decades as an essential agreement, placed by many Americans nearly on the level of the Constitution itself. It settled the immediate crisis and kept the peace for more than 20 years. But it also, as Jefferson had warned, institutionalized the geographic division it was meant to manage.

  The Compromise stopped the Southern progression of gradual emancipation at Missouri's southern border and legitimized slavery as a specifically Southern institution in federal law. The three-fifths clause, which counted three-fifths of the enslaved population for calculating congressional representation and Electoral College votes, continued to give the South influence in the federal government beyond what its free population alone would have justified. Northern critics had argued since the 1787 Constitutional Convention that this arrangement unfairly inflated southern power. Senator Rufus King of New York, a signatory to the Constitution who had strongly opposed the federal ratio in 1787, revived his critique in the 15th Congress debates in 1819, declaring himself politically degraded by the slaveholders' advantage.

  The Compromise Line itself was tested repeatedly. Extension of slavery westward arose again during the Texas Annexation in 1845, during the Compromise of 1850, and as part of the proposed Crittenden Compromise in 1860. The line never reached the Pacific. Stephen Douglas's Kansas-Nebraska Act of 1854 effectively repealed the ban on slavery north of 36 degrees 30 minutes, provoking what one account described as outrage across the North and drawing Abraham Lincoln back into active politics. The Supreme Court's ruling in Dred Scott v. Sandford in 1857 then declared the Compromise unconstitutional entirely, stripping away the legal foundation that had nominally constrained slavery's spread for a generation. Forty years after the compromise line was drawn, the North and South split closely along the 36 degrees 30 minutes parallel and launched the Civil War.