The Missouri compromise of 1820 involved land gain from

The Missouri Compromise of 1820 involved the land gained from the Louisiana Purchase of 1803. The compromise was a legislative agreement intended to maintain the balance of power between slave states and free states. The core issue was whether Missouri should enter the Union as a free state or a slave state. When it was proposed for Missouri to join as a slave state, this threatened to upset the balance, as there were then an equal number of slave and free states.

The Missouri Compromise provided that Missouri would be admitted to the Union as a slave state, but slavery would be prohibited in all remaining territories acquired from the Louisiana Purchase, north of the 36° 30' parallel, which was north of the southern border of Missouri. Additionally, as part of the compromise, Maine was admitted to the Union as a free state to maintain the balance between free and slave states in Congress.

Extra: The Missouri Compromise was significant in American history as it was an early attempt to resolve the division and conflict between the North and South over the issue of slavery. The compromise was seen as a temporary solution but did not address the underlying problem. It highlighted the sectional tensions that would eventually lead to the American Civil War in the 1860s.

The 1820 compromise lasted for over 30 years until it was effectively repealed by the Kansas-Nebraska Act of 1854, which allowed for popular sovereignty, or the right for residents of territories to vote for or against slavery, without regard to the earlier compromise line. This act led to further conflict and violence, notably in "Bleeding Kansas" as pro-slavery and anti-slavery settlers clashed over the legal status of slavery in the Kansas Territory. The Missouri Compromise's repeal by the Kansas-Nebraska Act and the subsequent Dred Scott decision in 1857, which stated that Congress did not have the authority to prohibit slavery in the territories, pushed the nation closer to the Civil War.