"And it was on record in America as law that we as black people were not considered fully humans."
This is something that people continue to say that is not really true. The "3/5 Compromise" is where slave holding states were granted the right to count 3/5 of their slave population when apportioning the number of a state's representatives in Congress.
It never mentioned anything about the humanity of Black people/the slaves. It really was about taxes and how much each state would be taxed.
Racist people spread the propaganda that Black people where less than human and cherry-picked wording from the 3/5 Compromise to falsely claim Congress had enacted a "law" proclaiming such.