Horrible things happened in the long distant past and the near distant past and still does today. We can't change the past, in hindsight it was cruel but it was normal trade in those days. As with many things in the past (like racial segregation in the USA) it is now considered crazy, but was normal at that time.
Don't dwell on what happened in the 14th, 15th and 16th centuries, look at today, slave nail bar, sex workers - the list is endless. We all need to be constructive and do positive things (I don't know what, I'm not a politician), but until the world leaders recognise the situation, it will continue because (at the risk of sounding American) it is worth big bucks to the slave traders.
Col