- When the issue of Missouri statehood was first considered by the U. S. House of Representatives in 1819, New York Congressman James Tallmadge introduced an amendment that provided that the further introduction of slaves into Missouri should be forbidden and that all children of slave parents born in the state after its admission should be free at the age of 25.
- The Missouri Compromise was authored by Senator Jesse B. Thomas of Illinois.
- The Missouri Compromise 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). The Compromise also prohibited slavery in the remainder of Missouri Territory north of the southern border of Missouri (36°30′ north latitude).
- 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.
- The Missouri Compromise was enacted by Congress on March 5, 1820, and ratified by President James Monroe on March 6.
- A Second Missouri Compromise was required in 1821 Missouri submitted its state constitution to Congress containing a provision that excluded “free negroes and mulattoes” from the state.
- Maine became the 23rd state on March 15, 1821
- Missouri became the 24th state on August 10, 1821
- The Missouri Compromise temporarily muffled the debate over slavery in the United States, although the abolitionist movement continued to grow in the North.
- The Missouri Compromise established the precedent that Congress could regulate slavery in the territories even though the Constitution did not address the issue.
- The key provisions of the Missouri Compromise regarding slavery were effectively repealed by the Kansas-Nebraska Act of 1854, which was based upon Illinois Senator Stephen Douglas’s promotion of the concept of popular sovereignty within the territories.
- In 1857, the U.S. Supreme Court’s decision in the case of Dred Scott v. Sandford sounded the death knell of the Missouri Compromise by ruling that Congress did not have the authority to prohibit slavery in territories.
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. Image Source: Library of Congress.