Missouri Compromise: Slavery Expansion Codified by Latitude

Congress admitted Missouri as a slave state and Maine as a free state, then drew the 36°30' line across the Louisiana Territory: slavery permitted south of the line, prohibited north of it. The compromise legitimized the westward expansion of slavery as a constitutional bargain, protecting the institution across a vast new domain. It also explicitly barred Congress from interfering with slavery in Missouri and set the template for future sectional deals that repeatedly deferred emancipation.