The Missouri Compromise of 1820 attempted to balance the expansion of slavery and free states by admitting Missouri as a slave state and Maine as a free state, while prohibiting slavery in the Louisiana Territory north of the parallel 36°30′ north except within the boundaries of Missouri. This compromise helped delay conflict over the issue of slavery and maintaining the balance of power between free and slave states for 30 years until it was overturned by the Kansas-Nebraska Act of 1854.