Thomas Sowell said this quote

It takes no more research than a trip to almost any public library or college to show the incredibly lopsided coverage of slavery in the United States or in the Western Hemisphere, as compared to the meager writings on even larger number of Africans enslaved in the Islamic countries of the Middle East and North Africa, not to mention the vast numbers of Europeans also enslaved in centuries past in the Islamic world and within Europe itself. At least a million Europeans were enslaved by North African pirates alone from 1500 to 1800, and some Europeans slaves were still being sold on the auction blocks in the Egypt, years after the Emancipation Proclamation freed blacks in the United States.