in the south, kentucky was created as a slave state from a part of virginia (1792). tennessee was created a slave state out of a part of north carolina (1796). by 1803, after ohio had been admitted to the united states, there were nine free states and eight slave states. the geographic divide between northern free states and southern slave states became the mason–dixon line. in 1820, the missouri compromise extended the mason–dixon line westward as the official dividing line between free and slave states east of the ohio river.