---
title: "Missouri Compromise of 1820 — APUSH Definition & Exam Guide"
description: "The Missouri Compromise of 1820 balanced free and slave states with the 36°30' line. See how APUSH links it to Kansas-Nebraska, Dred Scott, and Period 5."
canonical: "https://fiveable.me/apush/key-terms/missouri-compromise-of-1820"
type: "key-term"
subject: "AP US History"
---

# Missouri Compromise of 1820 — APUSH Definition & Exam Guide

## Definition

The Missouri Compromise of 1820 was an agreement passed by the United States Congress to maintain the balance of power between free and slave states. It admitted Missouri as a slave state and Maine as a free state, while establishing a line at latitude 36°30' north, north of which slavery would be prohibited in the Louisiana Purchase territory. This compromise aimed to ease tensions between the North and South regarding the expansion of slavery.

## Related Study Guides

- [5.5 Sectional Conflict: Regional Differences](/apush/unit-5/sectional-conflict-before-civil-war/study-guide/Klx3eOhZBS11qtWKIvH2)

## Review

### Related Terms

- Compromise of 1850: A series of laws aimed at settling disputes over slavery between free and slave states, including the admission of California as a free state and the implementation of a stricter Fugitive Slave Act.
- [Kansas-Nebraska Act](/apush/key-terms/kansas-nebraska-act): An 1854 law that created the territories of Kansas and Nebraska, allowing the settlers in those territories to determine if they would allow slavery, effectively repealing the Missouri Compromise.
- [Sectionalism](/apush/key-terms/sectionalism): The division of society or politics into different regions, often resulting in conflict over issues such as slavery, economy, and political representation.

### Key Facts

- The Missouri Compromise was introduced by Henry Clay, who sought to address growing tensions between pro-slavery and anti-slavery factions in Congress.
- The compromise resulted in Missouri being admitted as a slave state and Maine as a free state to maintain an equal number of slave and free states in the Union.
- The established boundary at 36°30' north served as a dividing line for future states carved out of the Louisiana Purchase regarding the legality of slavery.
- Although the Missouri Compromise temporarily eased sectional conflict, it set a precedent for future debates about the expansion of slavery, leading to further divisions.
- The compromise was ultimately rendered ineffective by subsequent legislation, including the Kansas-Nebraska Act of 1854, which allowed popular sovereignty to decide on slavery in new territories.

### How did the Missouri Compromise address the issue of sectional conflict between free and slave states?

The Missouri Compromise aimed to reduce sectional conflict by admitting Missouri as a slave state and Maine as a free state, thus maintaining a balance of power in Congress. Additionally, it established a geographical boundary at latitude 36°30' north that prohibited slavery in future states north of this line. This arrangement temporarily eased tensions but highlighted the deep divisions between pro-slavery and anti-slavery factions that would continue to escalate.

### Analyze how the Missouri Compromise influenced later legislative efforts regarding slavery in the United States.

The Missouri Compromise set a critical precedent for addressing the contentious issue of slavery in newly admitted states. It demonstrated Congress's willingness to create compromises to manage sectional differences but also exposed the limitations of such measures. The eventual repeal of the compromise by the Kansas-Nebraska Act illustrated how the underlying conflicts over slavery could not be fully resolved through temporary agreements, paving the way for further turmoil leading up to the Civil War.

### Evaluate the long-term effects of the Missouri Compromise on American politics and society leading up to the Civil War.

The long-term effects of the Missouri Compromise were profound, as it both alleviated immediate tensions between free and slave states while simultaneously sowing seeds for future conflict. By establishing a boundary for slavery in new territories, it highlighted regional divisions that would become increasingly polarized. The failure of subsequent compromises and the rise of sectionalism culminated in escalating violence, notably exemplified by events like 'Bleeding Kansas,' ultimately contributing to the outbreak of the Civil War. Thus, while it sought to maintain harmony within Congress, it inadvertently intensified divisions within American society.