You are welcome to draw your own metaphorically resonant conclusions from this fact. One of the big misconceptions about slavery, at least when I was growing up, was that Europeans somehow captured Africans, put them in chains, stuck them on boats, and then took them to the Americas. The chains and ships bit is true, as is the America part, if you define America as America and not as Merica. But Africans were living in all kinds of conglomerations, from small villages to city-states to empires, and they were much too powerful for the Europeans to just conquer. And in fact, Europeans obtained African slaves by trading for them. Because trade is a two-way proposition, this meant that Africans were captured by other Africans and then traded to Europeans in exchange for goods, usually like metal tools or fine textiles or guns. And for those Africans, slaves were a form of property, and a very valuable one.