Getting There wrote:
@newredsun above, you are off the mark on this. The 3/5 Compromise was a power play by the southern states. Northern states agreed to it because a) they needed those states to ratify the Constitution and b) most northern delegates were concerned with tariffs and trade; they didn't care about human rights either.
The 3/5 clause was in no way a "step toward abolition." It gave disproportional power to southern states, who gained the political representation of millions of humans who were denied any kind of political voice for almost a century after the ratification of the document.
There should be a Four-Fifths clause that if you alter your genitals you lose your right to vote and must live in a designated community.