What term was used to describe the rough ride between free and slave states by the mid 1800s

The answer is:  Mason-Dixon Line

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.

i honesty don't know, good luck tho dawg

well that depends on how deep the hole is. you'd first go through te crust of the earth, then the upper mantle, then the lower mantle then the outer core, then the inner cor then you'd be stuck in the core to melt.