Answer:
The expansion of slavery led to the mason dixon line, a line that seperated free states and slave states. This decision was controversial because some states did not know what side of the line they should be on due to differing views of the people within those border states. The mason dixon line also led to slaves changing their locations to be in free states. This aggitated slave owners.
Explanation:
In the future, specify a country and a time period so we know exactly what your talking abt, i hope u r talking in the US. You probably are.
