It appears to be in the essential nature of the Black sub-species to enslave others, including their own kind -- a practice that continues to this day in many parts of the African continent, such as, Mauritania, Mali, Nigeria, Chad, Sudan, et al. The simple reality is the White sub-species has abandoned the practice of slavery whereas Blacks have not. It appears to be an embedded characteristic of their culture.
And you may rest assured I will be denounced as a "racist" for making this simple academic observation.