The slave states or the southern states were benefited most from the three-fifths compromise.
Explanation:
The Three- Fifths compromise was concerned with counting the enslaved population in the southern states for the purpose of taxation and representation for the central government.
Three out of every five slaves were to counted and hence it is called three- fifth compromise. The enslaved population was counted in southern states. and it gave more power to the southern states then it would have given them if the slaves were not to be counted.