Fair enough but not the practice of slavery, which is what I meant, and was the point I intended to make by linking to info on modern African slavery.
It is a minor point, but I think it is important for people to realize that the transatlantic slave trade was banned by US law in 1808.
Another point of which most people are unaware is that the US Constitution effectively protected slavery in the US, but people just started ignoring this embarrassing constitutional provision.