Do you mean history of the African people in the context of them before European colonization or after the powers of Europe decided to divide Africa a conquer it?
I ask before there were many administrations which treated the local African people in a very cruel and inhumane way during the process of exploitation of natural resources and I would be quite a surprise to me if historians of those same countries would be willing to openly admit on the crimes they committed against entire populations for the sake of power and wealth. It is quite similar to the case of the empire of Japan and it's colonies, The japanese commited crimes against humanity and performed cruel experiments on people from the peninsula of Korea, it is well documented and there is enough proof of it, though, no japanese historian of that time dared to mention it, even to this day there are Japanese politicians willing to deny the obvious crimes the Empire of Japan carried out against people in their annexed colonies.