By an Act of Congress on March 6, 1820, Missouri was enabled to be admitted to the Union as a slave state, while slavery was forbidden in the rest of the Louisiana Purchase north of 36° 30' north latitude. The proposal marked the first great debate over the territorial expansion of slavery. On May 30, 1854, the Kansas-Nebraska Act repealed section 8 of the Missouri Compromise, its most important provision, and created the Kansas and Nebraska Territories. The 36° 30' north latitude line is the south border of Missouri, except for the Boot-heel, and the south border of the Oklahoma Panhandle.