Missouri Compromise Map (1820) - Free vs. Slave States & Territories #2241983 (License: Personal Use)

The map highlights key regions including the unorganized territory, Oregon Country under joint U.S.-British control, and the Spanish-U.S. treaty line of 1819. It clearly marks Missouri’s admission as a slave state in 1821 and Maine as a free state in 1820, with the 36°30′ parallel serving as the dividing line for future states’ status. Hatching distinguishes free soil (dots) from slave territories (solid white).

Used in educational history resources, museum exhibits, and academic articles about antebellum U.S. politics; serves users researching the origins of sectional conflict leading to the Civil War.