The 13th amendment establishes the right of the state to own slaves.
Technically, according to the text of the 13th amendment, it formally and legally establishes as a constitutional right of the state to declare people slaves as "punishment for crime whereof the party shall have been duly convicted", which has of course resulted in prison chain gangs and various corporations hiring prisoners for cheap compliant slave labor over the years, and in the demand for such slave labor and thus the motivation of the state to imprison as many people as possible.