An idiot says: Here's some of it. If you want to get your answers on political topics from the ultra-liberal Wikipedia - and thus, want the kind of answer a self-righteous idealogue would give - that's your business. If you want something frank and honest, you can always read this:
Comparatively speaking, it wasn't. Slaves were treated much more poorly outside of the U.S., and in non-European countries, than they were in the U.S. The only difference is that in the U.S., those who scream "victim" the loudest are given the greatest number of handouts. Other nations don't tolerate that nonsense.