What term was used to describe the rough divide between free and slave states by the mid-1800s. The Mason-Dixon line (between Maryland and Pennsylvania or Delaware)-was used to describe the rough divide between free and slave states by the mid-1800s.
Mason-Dixon Line marked the northern limit where slavery was still allowed in united states (if you move one stop north from the mason-dixon line, you could be in jail if you owned a slave).
The line has not been moved for around 150 years before eventually the missouri compromise was made and reduce the area where slavery was still allowed.
If you are talking about the time around slavery then, the north wanted to wourk out diffrences because they didnt want slavery but didnt want war either
