That's fair, Henry38
At least it explains to me how you might not know that. It's not, however, anything difficult to find out ... just pick up a book on beginnings of slavery in the United States and you're bound to read about it. It's been very well documented. It is part of our history.
I used to think that the reasons you would say some of the things you did were because you were African. It's not, it's because you're British! It's amazing how alike ... and very, very different our two lands are.
It would be facinating to be able to understand you one day!