Although the Three-Fifths Compromise helped Northern and Southern states reach an agreement that allowed for ratification of the Constitution, in the long run it had a negative effect on he nation because

It helped increase the number of slaves traded. It gave the south the power to outvote the north It limited the number of states that allowed slavery

Explanation:

nothing certain is known about what happened, but it seems that the country declined gradually, perhaps due to bad government, or, more likely, due to a series of bad harvests, which resulted in widespread and recurrent famine.