The Virginia plan advocated for a legislative branch where representation was based on state size. New Jersey proposed a plan that gave all states equal representation regardless of size.
Because some of representation was based on population size, an issue was raised over if slaves should be counted in the population or not. Southern states thought that they should, Northern states thought that they shouldn't.
The southern States didn't want the gov to be able to tax exports and they wanted the states to have the power to regulate the trade. The northern states disagreed.
The Connecticut Compromise kept a bicameral legislature. One house has proportional representation based on state size, and the other house was weighted equally among the states.
The Three-fifths Compromise provided that 3/5 of the slaves would be counted into a state's population.
This compromise allows Congress to regulate trade, but not to tax exports.