The US still permits slavery (as punishment for a crime):

https://en.wikipedia.org/wiki/Penal_labor_in_the_United_Stat...

Only counting slaves traded over the Atlantic is already a cop out.

One will say that communism, fascism and socialism enslave, and other will say that capitalism does. What was the difference between a concentration camp, gulag or a plantation? How far they are from the modern slavery from Bolivians in Brazil? Food for thoughts