What Obama myopically fails to mention is that slavery existed for thousands of years across nearly every major civilization long before the 1500s: ancient Mesopotamia, Egypt, Greece, Rome, China, India, pre-colonial African kingdoms, the Islamic world, and the Americas (Indians). It was not invented by or limited to the colonial Americas or European exploration. It was as omnipresent as Smallpox.

Africa and the Middle East had independent, long-standing traditions of slavery predating and outlasting much of the transatlantic slave trade. European involvement was significant but not the whole story, and the spontaneous morally driven Western abolitionism in the presence of real finance incentive to continue with it represented a real break from prior human norms. So, the US didn't create slavery. It was a worldwide institution when the country was founded. They abolished it and fought their bloodiest war to do so.

If you are going to talk about history tell the whole story.