History doesn’t lie.
It is absolutely true that less than two-hundred years ago black people were bought and sold and it was a perfectly legal transaction. It is absolutely true that humanity is capable of doing such horrible things to his fellow human.
What also is tragic is that for thousands of years Africans sold their brother and sisters to other tribes, to the highest bidder. Human labor was a commodity.
There are a few reasons why the Black men seemed to fall victim more often to slavery than most other peoples, part of it geographical, part of it had to do with climate, but most of it was because Africa is such a large place, there were just too many settlements, tribes, cultures, languages and traditions that never coalesced into a cohesive core continental government, where a single, common language could have given the African a better way to fight off his neighbors to the north as the Dutch, Spaniards, Middle Eastern and English others came to subjugate the individual tribes while poaching laborers, setting them apart from one another.