This is another interesting conspiracy theory that circulates on the Internet. Contrary to popular belief, the 14th amendment *LEGALIZED* slavery. The 14th amendment states:
No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United StatesThis is a departure from the original intent of the Constitution. Originally, the Constitution said that people had intrinsic rights and the government was restricted in its activities. The Federal government's powers were specifically enumerated, and all other rights were held by states or individual people. The 14th amendment says that people have privileges granted by the government. There is no mention of intrinsic rights anymore.
That is the change in perspective that the 14th amendment indicates. People have no intrinsic rights. They merely have privileges granted by the government.
Also, the 14th amendment was used as justification for corporate personhood. The Supreme Court interpreted the 14th amendment as allowing corporations to have the right of property ownership and the right of contract enforcement. I read that the Supreme Court has cited the 14th amendment ten times as often to support the rights of corporations, than to support the rights of individuals.