I strongly suggest for anybody who has a problem with what I said to actually just read the Wikipedia article about the Atlantic slave trade. Litterally the second sentence of the article is:

The vast majority of those who were transported in the transatlantic slave trade were people from Central and West Africa who had been sold by West African slave traders to mainly Portuguese, British, Spanish, Dutch, and French slave traders.

Obviously this is a dark chapter in human history, which makes it even more necessary to say the truth about it, as to not repeat it. Also really important is to read the part about what Africans did know about the slave trade, which was more then you seem to believe..

I hope you read it, as only the truth can help prevent something like this to happen again.