Slavery is still legal. It is authorised by the 13th amendment:
"Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction."
That's right, here in the land of the free, anyone convicted of any crime can legally be made a slave.
Is it any wonder that the United States houses a quarter of the world's prison population, yet is only 5% of the world's total population? Is it any wonder that 75% of prisoners in the US are black? Is any wonder we have for-profit prisons?
The language in the 13th amendment that authorises slavery must immediately be removed and all convicts be paid federal minimum wage.