when did sectional differeneces over the topic of slavery begin between the north and the south? 1776, 1820, 1850 or 1857

 The South was an agrarian economy based on slavery, while the North in this period was developing its industrial base. The Northern states had no slavery and a more equalitarian society, although large class disparities existed

i would think it's industries and hydroelectric power

i see, would you mind putting it as one?