The Three-Fifths Compromise dealt with the issues of slavery and representation in the House of Representatives. The compromise ended up establishing that three-fifths of all slaves would be counted for the purpose of determining how many representatives a given state would have in the House of Representatives.
In the Great Compromise, the Framers created a House of Representatives in which states would have a number of representatives proportional to their population. States with larger populations would have more representatives. When this was decided, the delegates from states with many slaves wanted to make sure that slaves would be counted as part of the population of their states. If they got their way, their states would have more representation in the House. The delegates from the states that did not have slaves did not want the slaves to be counted at all. As a compromise, it was decided that three-fifths of the slaves would be counted in the states’ population for the purpose of determining how many members each state would have in the House of Representatives.