Free and Slave Areas in the United States, 1821 Map #2241992 (License: Personal Use)

The map depicts the geographic political split in the United States following the Missouri Compromise of 1820, which admitted Missouri as a slave state and Maine as a free state. Territories north of the 36°30′ parallel (except Missouri) were designated free, while those south could permit slavery. Key regions labeled include the Northwest Territory (yellow), Arkansas Territory (purple), and individual states like Missouri (red) and Maine (red).

Used in educational history resources, museum exhibits, or digital archives to explain antebellum U.S. sectionalism and the origins of the Civil War; matches user intent for historical geography, slavery studies, or curriculum support.