Although the three-fifths compromise northern and southern states reach an agreement that allowed for ratification of the constitution, in the long run it had a negative effect on the nation because

This is because it gave more opportunities for the slave states.  Though Blacks were part of the equation, they were not really given rights because they were slaves and were considered property.  The use of the numbers would justify the representation of a state through the inclusion of slaves.  Later on, this debate would lead to conflict between states during the Civil War.

the answer is expolration. hope this !