"For we got rid of things like having slaves be counted as 3/5 of a person of representation."

Just in case you didn't know, the "a slave is 3/5 of a person" that is so oft-decried today was an anti-slavery measure. For the purposes of Congressional representation, if a slave was counted as a full person, then the slave-owning states would get expanded numbers in Congress for all the non-voters being kept in slavery. Three-fifths, as opposed to full representation, at least kept them from gaining as much power as they would have otherwise. These things generally aren't as simple as one is often told.