One of my biggest pet peeves is many arguments by the paler nation that Africans sold slaves to them. In the beginning it was true but even so they did so with what they knew in their minds as slaves to be.
But once this started and it began to actually impact all parts of the African region, there were attempts to stop this. But greedy business owners hired villainous pirates to capture and smuggle human cargo and they did so to the tune of millions. I read one recount of a former slave who said his grandmother came from Africa and was one of many who was tricked to go onto a boat with candy. After they loaded the boat they shut everyone in and shot anybody who tried to leave.
Here is an argument from one abolitionist: