TopTenz
Slavery is improper. That's the sort of massively uncontroversial statement we can probably all get onboard with (whether not,maybe it's time to re-examine your life, Mr. I still live in the 18th Century). No matter who is enslaving whom or what they're doing with all that concentrated human power, and it's almost guaranteed to be a improper conception. Yet that doesn't mean we've scrubbed absent all the traces of this exceptionally improper conception from our contemporary world. Far from it. Go traveling around the Americas,Europe, Africa or the Caribbean and you'll find entire cities that were built on the groaning backs...
Source: realclearhistory.com