The Tallmadge Amendment was a proposed amendment to a bill regarding the admission of the Territory of Missouri as a state, under which Missouri would be admitted as a free state. The amendment was submitted in the U.S. House of Representatives on February 13, 1819, by James Tallmadge Jr., a Democratic-Republican from New York.
In 1820, the Missouri Compromise was passed without the Tallmadge Amendment. The Compromise attempted to appease both sides of the debate by admitting Missouri as a slave state in exchange for the admission of Maine as a free state and by the complete prohibition of slavery in all of the remaining Louisiana Purchase territory north of the 36˚30’ parallel.