Ch. 4.1. Primary Source: The Missouri Compromise, 1820
When in 1819 Missouri applied for statehood, with a state constitution that allowed slavery, controversy erupted in Congress. At the time the twenty-two states were evenly divided between free and slave states, and many northerners opposed the imbalance that the admission of Missouri as a slave state would create.
Northern opposition to the admission of Missouri as a slave state crystallized in an amendment to the bill for Missouri statehood proposed in the House in early February, 1820, by Representative James Tallmadge of New York. The Tallmadge Amendment, which passed in the House, proposed to phase out slavery in Missouri by prohibiting the movement of slaves into the state and freeing any children born into slavery within the state when they reached the age of twenty-five. Although the amendment was rejected by the Senate, many southern leaders were enraged by the idea that the federal government would consider overriding a state’s preference for slavery. Some suggested that such actions would lead to the eventual secession of the South.
Southern fears that federal power would be used against slave-state interests were based partly on the fact that the North’s population, which had been larger than that of the South since the founding, had begun to grow much faster. This growth reinforced northern dominance of the House of Representatives, and led southern leaders to focus ever more insistently on maintaining southern representation in the Senate at least at parity.
The Missouri Compromise. Led by Henry Clay of Kentucky, the Speaker of the House, Congress agreed on a compromise that got enough northern support for the admission of Missouri as a slave state, in return for two things. First, Maine, which until then had been claimed by Massachusetts, was admitted as as a free state. Second, slavery was prohibited in that part of the lands bought from France in the Louisiana Purchase of 1803 that was north of the 36º 30´ latitude line. This line corresponded to Missouri’s southern border, and it meant most of this territory would become free states (Kansas, Nebraska, Iowa, the Dakotas, etc.). It also meant that, besides Louisiana, which had already been admitted in 1812 as a slave slave state, only one additional slave state would be formed from the territory below the 36-30 line, Arkansas, in 1836. Most of Oklahoma was also south of this line, but it did not become a state until 1907.
Aftermath. Many northerners welcomed this compromise and in particular the prohibition of slavery in most of the western territories acquired from France. Over time this prohibition took on a status almost like that of the Constitution itself in the North–as a permanent feature to guarantee sectional harmony. In contrast, many southerners considered this a bad deal at the time, and perhaps even an unconstitutional one. The provision held for 34 years, until it was repealed by the Kansas-Nebraska Act of 1854.
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. March 6, 1820.
SEC. 1. Be it enacted…, 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…; 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…, are hereby qualified and authorized to vote, and choose representatives to form a convention…
SEC. 4. …and which convention…, is authorized to form 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. 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 labor 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 labor or service as aforesaid.
Sources: The National Archives’ “Our Documents” website, under the Missouri Compromise; the Library of Congress’s “Primary Documents in American History,” in the section on “National Expansion and Reform,” under the Missouri Compromise (with many related documents); and Teaching American History.org, under the Missouri Compromise (text only).