What central issue did the Missouri Compromise of 1820 address?

The Missouri Compromise of 1820 was primarily concerned with the balance of power between free and slave states in the United States as the nation expanded westward. This compromise emerged in response to Missouri's application for statehood as a slave state, which threatened to upset the delicate balance established by previous legislation.

To resolve this issue, the compromise admitted Missouri as a slave state while simultaneously allowing Maine to enter as a free state, maintaining the equilibrium in Congress. Additionally, the compromise established a geographic boundary at the 36°30' parallel, north of which slavery would be prohibited in the remaining territory of the Louisiana Purchase. This arrangement was intended to provide a temporary solution to the contentious issue of slavery in new states and territories, reflecting the deep-seated divisions in American society regarding slavery. Thus, it is clear that the Missouri Compromise directly addressed the critical issue of maintaining a balance of power in the context of free and slave states.