ARE WE REALLY CITIZENS?

So-called Blacks in America are quick to check in the little boxes that they're citizens of The United States of America. Being the product of former slaves... When our ancesters were "Set Free", there were no reparations, nor did we ever take an oath of citizenship here in America. Does being born here reallt make us AMERICANS, and if so why are we still considered 3/5 of a person according to The U.S. Constitution? Why do we as a citizen need to be granted permission to vote?