What compromise allowed Missouri to enter as a slave state and Maine as a free state in 1820?

The Missouri Compromise, established in 1820, resolved the sectional conflict between slave and free states by allowing Missouri to join the Union as a slave state while Maine entered as a free state. This was significant because it maintained the balance of power in Congress between slave states and free states, which was crucial to governing the increasingly divided nation. The compromise also included a provision that prohibited slavery in the northern part of the Louisiana Territory, which further defined the boundaries for the practice of slavery in future states. This compromise was an early attempt to manage the growing tensions around the issue of slavery and demonstrated the complexities of balancing interests in a rapidly expanding United States.