Missouri Compromise
US (now historical )
noun
The measure passed by the U.S. Congress in 1820 (and repealed in 1854) which provided that Missouri should be admitted to the Union as a Slave State, but forbade slavery in any other part of the Louisiana Purchase lying north of the latitude 36° 30′.
Origin
Early 19th century; earliest use found in Thomas Hart Benton (1782–1858).