The question of admitting Missouri to the United States divided the nation, because people argued if Missouri should be a slave state or a free state. Debate raged in Congress over a proposal to ban slavery in Missouri. Angry Southerners claimed that the Constitution did not give Congress the power to ban slavery. They worried that free states could form a majority in Congress and ban slavery altogether.
In the early 1800s, conflict did indeed arise in the national legislature-chambers of the United States when Missouri requested admission into the Union. As a slave-holding territory, Missouri would presumably enter the Union as yet another slave-holding state, which would lend additional strength to the already strong contingent of slave-holding states in the American South. Thus, Southern politicians shrewdly pushed for the admission of Missouri, while Northerners shrewdly sought to put up barriers to it.
Missouri believed in slavery and wanted to come in as a slave state. This was a problem because the number of Senators is two per state; if Missouri had more senators that supported slavery, the votes would be unbalanced.
The government basically wanted a chance to have votes be more equally balanced. So, Missouri had to wait until Maine wanted to come in as a free state. That way, potential votes had a higher chance to stay even. It's called the Missouri Compromise.
Missouri compromise
Missouri became the 24th state admitted to the Union on August 10, 1821.
Maine became the 23rd state on March 15, 1820. Its admission to the Union balanced the simultaneous admission of Missouri as a slave state.
The Tallmadge Amendment requested that the territory known as Missouri become a part of the Union. It also demanded that there be no slavery in Missouri if it was admitted to the Union.
Missouri itself. IMPROVEMENT The State of Maine, to balance the number of Free States and Slave States after the admission of Missouri as Slave State in the Union.
admitting Maine to balance the slave issue ( answer for A + )
The admission of California into the Union. It extended too far either side of the Missouri line to satisfy either side.
Under the Missouri Compromise of 1820 Missouri was admitted as a slave state and Maine as a free state.
It remained loyal to the Union, and that is why Lincoln allowed slavery to continue there. But it was a badly divided state, with guerrilla warfare continuing throughout the conflict.
A sensible compromise, whereby Missouri would be allowed to join the Union as a slave-state, but after that there would be no slavery allowed, North of the parallel that marked Missouri's Southern border, in any of the territories acquired through the Louisiana Purchase.
You could be referring to Missouri in 1819/20 or California in 1850.
it caused slavery to expand in to the north.