The MAIN issue that the Missouri Compromise attempted to settle was:
1. Where to allow slavery.
The Missouri Compromise was an effort made in 1820 to address the issue of slavery in the expanding United States. It aimed to maintain a balance between free and slave states to prevent disputes over the expansion of slavery into new territories.
Under the Missouri Compromise, Maine was admitted as a free state and Missouri as a slave state, maintaining the balance between free and slave states. Additionally, it established a line (the 36°30' parallel) across the Louisiana Territory, stating that slavery would be allowed below this line and prohibited above it.
By addressing the question of where to allow slavery, the Missouri Compromise attempted to ease tensions between the North and the South regarding the expansion of slavery into new territories, showing how significant and contentious the issue of slavery was in shaping American history during this time period.