The proposal of admitting Missouri as a slave state rekindled the slavery conflict between the North and the South.
1. Free vs. Slave States: Prior to Missouri's admission, there was a 12:12 balance between free states and slave states. Missouri was crucial because admitting it as a slave state would upset the equilibrium, giving the South a larger number of pro-slavery senators.
2. Sectional Tensions: The Northern representatives began expressing fear that additional slave states would be allowed, which would give the South an undue influence in the federal government.
3. Anti-slavery Sentiment: The free states were home to a growing abolitionist movement, which adamantly opposed the spread of slavery. They regarded the admission of additional slave states as a blow to their cause and a violation of the principles of freedom and equality.
4. Compromise of 1820: In an effort to resolve the dispute over Missouri's statehood, Congress came up with the compromise of 1820. The agreement allowed Missouri to enter the Union as a slave state, but as compensation Maine was admitted as a free state. The 36° 30′ parallel was established to divide the Louisiana Territory, whereby any future states established north of the parallel would be free states, while any that were founded south of it would be slave states.
5. Missouri's Admission: Missouri was accepted into the Union as a slave state in August 1821, following a heated debate in Congress and a narrow vote in the Senate.
While the Compromise of 1820 temporarily pacified the North and South, it also highlighted the deep divide between them over the issue of slavery. The tensions that resulted from the discussions around the admission of Missouri would persist and eventually explode in the years to come, playing a significant role in the build-up to the American Civil war in 1861.