At the Missouri Compromise in 1819, Missouri applied for admission to the Union as a slave state. This sparked a major debate in the Senate on slavery. Northern congressmen believed it would create an imbalance in the relationship between slave states and free states. Therefore, a compromise was reached in 1820, the Missouri Compromise, according to which Missouri was incorporated into the Union as a slave state and Maine was incorporated as a free state. Furthermore, slavery was prohibited in the former Louisiana Territory to the 36° 30′ parallel.
Missouri would be admitted to the Union as a slave state, but then Maine would be freed. This would help balance the amount of slave and free states, putting the minds of the people at ease.
