In the years leading up to the Missouri Compromise of 1820, tensions began to rise between pro-slavery and anti-slavery factions within the U.S. Congress and across the country. They reached a boiling point after Missouri’s 1819 request for admission to the Union as a slave state, which threatened to upset the delicate balance between slave states and free states. To keep the peace, Congress orchestrated a two-part compromise, granting Missouri’s request but also admitting Maine as a free state. It also passed an amendment that drew an imaginary line across the former Louisiana Territory, establishing a boundary between free and slave regions that remained the law of the land until it was negated by the Kansas-Nebraska Act of 1854.
More to Explore
People and Groups
Slavery and its legacy have shaped American history, from the Civil War to Reconstruction in the 1860s and 1870s to the struggle over civil rights a century later.
The American Civil War, fueled by the debate over slavery and states' rights, pitted North against South in the costliest conflict fought on U.S. soil.
James Monroe served as America's fifth president from 1817 to 1825.
In 1794, American inventor Eli Whitney patented the cotton gin, a machine that revolutionized the production of cotton.
Did You Know?
For his work on the Missouri Compromise, Senator Henry Clay became known as the “Great Pacificator."
The Missouri Compromise was an effort by Congress to defuse the sectional and political rivalries triggered by the request of Missouri late in 1819 for admission as a state in which slavery would be permitted. At the time, the United States contained twenty-two states, evenly divided between slave and free. Admission of Missouri as a slave state would upset that balance; it would also set a precedent for congressional acquiescence in the expansion of slavery. Earlier in 1819, when Missouri was being organized as a territory, Representative James Tallmadge of New York had proposed an amendment that would ultimately have ended slavery there; this effort was defeated, as was a similar effort by Representative John Taylor of New York regarding Arkansas Territory.
The extraordinarily bitter debate over Missouri's application for admission ran from December 1819 to March 1820. Northerners, led by Senator Rufus King of New York, argued that Congress had the power to prohibit slavery in a new state. Southerners like Senator William Pinkney of Maryland held that new states had the same freedom of action as the original thirteen and were thus free to choose slavery if they wished. After the Senate and the House passed different bills and deadlock threatened, a compromise bill was worked out with the following provisions: (1) Missouri was admitted as a slave state and Maine (formerly part of Massachusetts) as free, and (2) except for Missouri, slavery was to be excluded from the Louisiana Purchase lands north of latitude 36°30′.
The Missouri Compromise was criticized by many southerners because it established the principle that Congress could make laws regarding slavery; northerners, on the other hand, condemned it for acquiescing in the expansion of slavery (though only south of the compromise line). Nevertheless, the act helped hold the Union together for more than thirty years. It was repealed by the Kansas-Nebraska Act of 1854, which established popular sovereignty (local choice) regarding slavery in Kansas and Nebraska, though both were north of the compromise line. Three years later, the Supreme Court in the Dred Scott case declared the Missouri Compromise unconstitutional, on the ground that Congress was prohibited by the Fifth Amendment from depriving individuals of private property without due process of law.
The Reader's Companion to American History. Eric Foner and John A. Garraty, Editors. Copyright © 1991 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Fact Check We strive for accuracy and fairness. But if you see something that doesn't look right, contact us!
This Day in History
Rosenbergs executed, 1953
On this day in 1953, Julius and Ethel Rosenberg, who were convicted of conspiring to pass U.S. atomic secrets to the Soviets, are executed at Sing Sing…
Find DVDs, CDs, & Books by Howard Zinn
Keep up with the latest History shows, online features, special offers and more.Sign up