Portrait of Henry Clay.

Henry Clay is often given credit for the passage Missouri Compromise because he used his considerable influence as Speaker of the House of Representatives to forge a consensus in Congress. [Library of Congress]

Missouri Compromise

March 6, 1820

The Missouri Compromise comprised legislation passed by the U.S. Congress in 1820 that attempted to resolve sectional disputes over the extension of slavery in western territories of the United States.



When delegates to the Constitutional Convention assembled in Philadelphia in 1787, one of the more daunting tasks that they faced was resolving sectional differences between the North and South centered on the issue of slavery. After weeks of debate proved futile, the delegates negotiated a series of compromises that enabled them to proceed with their primary assignment of forming “a more perfect Union” between the separate states. In the short term, the compromises regarding the status of slavery established in the Constitution facilitated the creation of the new republic (at the expense of blacks held in bondage), but they also sowed the seeds of turmoil that began coming to fruition as the nation expanded west in the coming decades.

The Northwest Ordinance

As the delegates to the Constitutional Convention set about creating a new government, representatives to the Congress of the existing government established under the Articles of Confederation were meeting in New York. On July 13, 1787, the Confederation Congress enacted “An Ordinance for the government of the Territory of the United States northwest of the River Ohio,” that stipulated “There shall be neither slavery nor involuntary servitude in the said territory,… ” That legislation, more commonly known as the Northwest Ordinance, had the effect of establishing the Ohio River as the border separating free and slave states between the Appalachian Mountains and the Mississippi River. For the next three decades, that boundary forestalled major sectional disputes over slavery.

The Louisiana Purchase

Circumstances changed in 1803 when Napoleon Bonaparte sold President Thomas Jefferson 828,000 square miles of land west of the Mississippi River. The Louisiana Purchase created new challenges for the federal government. Besides land ownership issues regarding the native inhabitants, Congress eventually had to address the question of the expansion of slavery in the new territory.

Missouri Statehood

In 1812, Congress carved the Missouri Territory out of the Louisiana Purchase. Settlers began pouring into the new territory, many of them slaveholders from the South. In 1818, when the residents of Missouri petitioned Congress for statehood, roughly 8,000 to 10,000 slaves lived in the territory.  In January, residents of the territory petitioned the U.S. House of Representatives for statehood, but the House did not consider the measure during that session. In December 1818, Missouri residents petitioned Congress for statehood a second time.

The Tallmadge Amendment

The House took up the request during the next session. Southerners expected Congress to admit Missouri as a slave state, but on February 13, 1819, New York Congressman James Tallmadge introduced an amendment to the Missouri statehood measure that would gradually end slavery in the new state. The Tallmadge Amendment also mandated the emancipation of all children of slaves born in the State of Missouri upon reaching the age of twenty-five. The Tallmadge Amendment started a year of bitter debate in both houses of Congress. On February 17, 1819, the House passed a bill recommending Missouri statehood, including the Tallmadge Amendment, by a vote of 82 to 78, and forwarded it to the Senate. The upper chamber never voted on the proposed legislation.


During the following session of Congress, on January 3, 1820, the House passed legislation to admit Maine to the Union as a free state. Later that month, the lower chamber revisited the proposal for Missouri statehood. On January 26, 1820, John W. Taylor of New York introduced an amendment allowing Missouri to enter the union as a slave state, which the House adopted.

The Senate tied the two bills together, passing a single bill admitting Maine to the Union and an amendment enabling the people of Missouri to draft a state constitution. The proposed legislation hinged upon an important second amendment introduced by Senator Jesse B. Thomas of Illinois. The original bill provided for a trade-off: admitting Maine as a free state in return for admitting Missouri as a slave state, thus maintaining the balance of power in the Senate (twelve free states and twelve slave states). As amended by Thomas, however, the bill also prohibited slavery in the rest of the Louisiana Territory, north of the southern border of the new state (36°30′ north latitude). The Senate passed the amended legislation and returned it to the House.

The amended Senate bill evoked considerable sectional rancor in the lower chamber. House Speaker Henry Clay had to use his considerable skills to forge a consensus. Eventually, he got his colleagues to enact two bills—one admitting Maine to the Union and another, which included the Thomas Amendment, enabling the citizens of Missouri to draft a state constitution with no restrictions upon slavery. Together, the two pieces of legislation became known as the Missouri Compromise. Congress passed the compromise legislation on March 5, 1820, and President James Monroe signed it into law the next day.

A Second Compromise

Missouri’s statehood request required a second compromise after Missouri submitted its state constitution to Congress in 1821. The proposed constitution contained a provision that excluded “free negroes and mulattoes” from the state. Once again, Clay demonstrated his abilities as the “Great Compromiser” by getting the Congress to allow the admission of Missouri to the Union provided that the exclusionary clause in the proposed constitution “shall never be construed to authorize the passage of any law . . . by which any citizen of either of the States in this Union shall be excluded from the enjoyment of any of the privileges and immunities to which such citizen is entitled under the Constitution of the United States.” Thus, by agreeing to never deny citizens of other states coming into Missouri, the rights afforded them by the U.S. Constitution, Missouri became the 24th state on August 10, 1821.


Besides settling the issues at hand, namely the admission of the states of Missouri and Maine to the Union, the Missouri Compromise had other important consequences. It temporarily muffled the debate over slavery (or at least the extension of slavery) in the United States, although the abolitionist movement continued to grow in the North. Beyond that, it also established the precedent that Congress could regulate slavery in the territories even though the Constitution did not address the issue. Three decades later, that precedent became the focal point of constitutional and states’ rights arguments that contributed to the attempted dissolution of the Union in 1860.

The slavery issue reached crisis proportions once again in 1850 when Congress struggled over the disposition of new territories acquired during the Mexican-American War. The Compromise of 1850, authored by Clay and shepherded through Congress by Illinois Senator Stephen Douglas, formally codified the concept of popular sovereignty, which Douglas and Michigan Senator Lewis Cass championed. In 1854, the Kansas-Nebraska Act (which also invoked popular sovereignty), gutted the key provision of Missouri Compromise regarding slavery in the Missouri Territory.  Three years later, the U.S. Supreme Court’s decision in the case of Dred Scott v. Sandford, nurtured the growth of the Republican Party, alienating Southerners even more. The election of Abraham Lincoln to the presidency in 1860, proved to be the death knell of the spirit of compromise. Ultimately, only the tragedy of four years of civil war would determine the future of the Union, and slavery in the United States.

Missouri Compromise Text

An Act to authorize the people of the Missouri territory to form a constitution and state government, and for the admission of such state into the Union on an equal footing with the original states, and to prohibit slavery in certain territories.

Be it enacted by the Senate and House of Representatives of the United States of America, in Congress assembled, That the inhabitants of that portion of the Missouri territory included within the boundaries herein after designated, be, and they are hereby, authorized to form for themselves a constitution and state government, and to assume such name as they shall deem proper; and the said state, when formed, shall be admitted into the Union, upon an equal footing with the original states, in all respects whatsoever.

SEC.2. And be it further enacted, That the said state shall consist of all the territory included within the following boundaries, to wit: Beginning in the middle of the Mississippi river, on the parallel of thirty-six degrees of north latitude; thence west, along that parallel of latitude, to the St. Francois river; thence up, and following the course of that river, in the middle of the main channel thereof, to the parallel of latitude of thirty-six degrees and thirty minutes; thence west, along the same, to a point where the said parallel is intersected by a meridian line passing through the middle of the mouth of the Kansas river, where the same empties into the Missouri river, thence, from the point aforesaid north, along the said meridian line, to the intersection of the parallel of latitude which passes through the rapids of the river Des Moines, making the said line to correspond with the Indian boundary line; thence east, from the point of intersection last aforesaid, along the said parallel of latitude, to the middle of the channel of the main fork of the said river Des Moines ; thence down arid along the middle of the main channel of the said river Des Moines, to the mouth of the same, where it empties into the Mississippi river; thence, due east, to the middle of the main channel of the Mississippi river; thence down, and following the course of the Mississippi river, in the middle of the main channel thereof, to the place of beginning : Provided, The said state shall ratify the boundaries aforesaid . And provided also, That the said state shall have concurrent jurisdiction on the river Mississippi, and every other river bordering on the said state so far as the said rivers shall form a common boundary to the said state; and any other state or states, now or hereafter to be formed and bounded by the same, such rivers to be common to both; and that the river Mississippi, and the navigable rivers and waters leading into the same, shall be common highways, and for ever free, as well to the inhabitants of the said state as to other citizens of the United States, without any tax, duty impost, or toll, therefor, imposed by the said state.

SEC. 3. And be it further enacted, That all free white male citizens of the United States, who shall have arrived at the age of twenty-one years, and have resided in said territory: three months previous to the day of election, and all other persons qualified to vote for representatives to the general assembly of the said territory, shall be qualified to be elected and they are hereby qualified and authorized to vote, and choose representatives to form a convention, who shall be apportioned amongst the several counties as follows :

From the county of Howard, five representatives. From the county of Cooper, three representatives. From the county of Montgomery, two representatives. From the county of Pike, one representative. From the county of Lincoln, one representative. From the county of St. Charles, three representatives. From the county of Franklin, one representative. From the county of St. Louis, eight representatives. From the county of Jefferson, one representative. From the county of Washington, three representatives. From the county of St. Genevieve, four representatives. From the county of Madison, one representative. From the county of Cape Girardeau, five representatives. From the county of New Madrid, two representatives. From the county of Wayne, and that portion of the county of Lawrence which falls within the boundaries herein designated, one representative.

And the election for the representatives aforesaid shall be holden on the first Monday, and two succeeding days of May next, throughout the several counties aforesaid in the said territory, and shall be, in every respect, held and conducted in the same manner, and under the same regulations as is prescribed by the laws of the said territory regulating elections therein for members of the general assembly, except that the returns of the election in that portion of Lawrence county included in the boundaries aforesaid, shall be made to the county of Wayne, as is provided in other cases under the laws of said territory.

SEC. 4. And be it further enacted, That the members of the conven tion thus duly elected, shall be, and they are hereby authorized to meet at the seat of government of said territory on the second Monday of the month of June next; and the said convention, when so assembled, shall have power and authority to adjourn to any other place in the said territory, which to them shall seem best for the convenient transaction of their business; and which convention, when so met, shall first determine by a majority of the whole number elected, whether it be, or be not, expedient at that time to form a constitution and state government for the people within the said territory, as included within the boundaries above designated; and if it be deemed expedient, the convention shall be, and hereby is, authorized to form a constitution and state government; or, if it be deemed more expedient, the said convention shall provide by ordinance for electing representatives to form a constitution or frame of government; which said representatives shall be chosen in such manner, and in such proportion as they shall designate; and shall meet at such time and place as shall be prescribed by the said ordinance; and shall then form for the people of said territory, within the boundaries aforesaid, a constitution and state government: Provided, That the same, whenever formed, shall be republican, and not repugnant to the constitution of the United States; and that the legislature of said state shall never interfere with the primary disposal of the soil by the United States, nor with any regulations Congress may find necessary for securing the title in such soil to the bona fide purchasers ; and that no tax shall be imposed on lands the property of the United States ; and in no case shall non-resident proprietors be taxed higher than residents.

SEC. 5. And be it further enacted, That until the next general census shall be taken, the said state shall be entitled to one representative in the House of Representatives of the United States.

SEC. 6. And be it further enacted, That the following propositions be, and the same are hereby, offered to the convention of the said territory of Missouri, when formed, for their free acceptance or rejection, which, if accepted by the convention, shall be obligatory upon the United States:

First. That section numbered sixteen in every township, and when such section has been sold, or otherwise disposed of, other lands equivalent thereto, and as contiguous as may be, shall be granted to the state for the use of the inhabitants of such township, for the use of schools.

Second. That all salt springs, not exceeding twelve in number, with six sections of land adjoining to each, shall be granted to the said state for the use of said state, the same to be selected by the legislature of the said state, on or before the first day of January, in the year one thousand eight hundred and twenty-five ; and the same, when so selected, to be used under such terms, conditions, and regulations, as the legislature of said state shall direct: Provided, That no salt spring, the right whereof now is, or hereafter shall be, confirmed or adjudged to any individual or individuals, shall, by this section, be granted to the said state: And provided also, That the legislature shall never sell or lease the same, at anyone time, for a longer period than ten years, without the consent of Congress.

Third. That five per cent. of the net proceeds of the sale of lands lying within the said territory or state, and which shall be sold by Congress, from and after the first day of January next, after deducting all expenses incident to the same, shall be reserved for making public roads and canals, of which three fifths shall be applied to those objects within the state, under the direction of the legislature thereof; and the other two fifths in defraying, under the direction of Congress, the expenses to be incurred in making of a road or roads, canal or canals, leading to the said state.

Fourth. That four entire sections of land be, and the same are hereby, granted to the said state, for the purpose of fixing their seat of government thereon; which said sections shall, under the direction of the legislature of said state, be located, as near as may be, in one body, at any time, in such townships and ranges as the legislature aforesaid may select, on any of the public lands of the United States: Provided, That such locations shall be made prior to the public sale of the lands of the United States surrounding such location.

Fifth. That thirty-six sections, or one entire township, which shall be designated by the President of the United States, together with the other lands heretofore reserved for that purpose, shall be reserved for the use of a seminary of learning, and vested in the legislature of said state, to be appropriated solely to the use of such seminary by the said legislature: Provided, That the five foregoing propositions herein offered, are on the condition that the convention of the said state shall provide, by an ordinance, irrevocable without the consent or the United States, that every and each tract of land sold by the United States, from and after the firsl day of January next, shall remain exempt from any tax laid by order or under the authority of the state, whether for state, county, or township, or any other purpose whatever, for the term of five years from and after the day of sale; And further, That the bounty lands granted, or hereafter to be granted, for military services during the late war, shall, while they continue to be held by the patentees, or their heirs remain exempt as aforesaid from taxation for the term of three year; from and after the date of the patents respectively.

SEC. 7. And be it further enacted, That in case a constitution and state government shall be formed for the people of the said territory of Missouri, the said convention or representatives, as soon thereafter as may be, shall cause a true and attested copy of such constitution or frame of state government, as shall be formed or provided, to be transmitted to Congress.

SEC. 8. And be it further enacted. That in all that territory ceded by France to the United States, under the name of Louisiana, which lies north of thirty-six degrees and thirty minutes north latitude, not included within the limits of the state, contemplated by this act, slavery and involuntary servitude, otherwise than in the punishment of crimes, whereof the parties shall have been duly convicted, shall be, and is hereby, forever prohibited: Provided always, That any person escaping into the same, from whom labour or service is lawfully claimed, in any state or territory of the United States, such fugitive may be lawfully reclaimed and conveyed to the person claiming his or her labour or service as aforesaid.

APPROVED, March 6, 1820. 


Citation Information

The following information is provided for citations.

  • Article Title Missouri Compromise
  • Coverage March 6, 1820
  • Author
  • Keywords missouri compromise, jesse burgess Thomas, henry clay, james Tallmadge, john w. taylor
  • Website Name American History Central
  • Access Date January 18, 2022
  • Publisher R.Squared Communications, LLC
  • Original Published Date
  • Date of Last Update February 11, 2021
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