According to the 1790 census, where did most enslaved people live? only in the north mostly in the south mostly in the mid-west only in the far west

The correct choice is:

According to the 1790 census slavery was mostly found "mostly in the South". 

A major reason for this was that they were dependent on slave labor for the crops. Although north also had slaves but comparatively south had it on a larger scale.

The correct answer on Edgen is:

(B.) mostly in the South

I took the test and this is the right answer.

b.   jim crow laws were enacted in northern states.