U.S. history concepts · AP U.S. History
Missouri Compromise
Missouri Compromise: The 1820 agreement that admitted Missouri as a slave state and Maine as a free state and banned slavery in the rest of the Louisiana Purchase north of 36°30′.
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What it means
The compromise preserved the balance between free and slave states in the Senate and drew a line for slavery in the western territories. It eased tensions for a generation but revealed how divisive slavery's expansion had become.
The Kansas-Nebraska Act of 1854 effectively repealed the line by allowing popular sovereignty in territories north of it.
Example
Thomas Jefferson described the crisis over Missouri as 'a fire bell in the night,' warning that it signaled future division.
On the exam
The Missouri Compromise is a frequent example in essays about the causes of the Civil War and the sectional crisis.
Lessons and practice questions
Related terms
- Popular sovereigntyIn the sectional crisis, the idea that settlers in a territory should vote on whether to allow slavery; more broadly, the principle that government's authority comes from the people.
- Manifest DestinyThe nineteenth-century belief that the United States was destined to expand across North America.