The impressive edifices such as the pyramids, Sphinx, temples, monuments bear witness to the greatness and accomplishments of the people -- and not to mentioned the incredible scholarship on religion, science, medicine, cosmology, mathematics and philosophy that are still being deciphered.
Second, the ancient West African empires of Ghana, Mali and Songhai are well documented. Arguably, the most famous and wealthiest emperor is Mansa Mush from Mali. Musa is best known for his epic 1324-1325 pilgrimage to Mecca.
It is said that Mansa Musa was extremely rich and that he brought as many as 60,000 people along with him on his pilgrimage. He also brought camels loaded with gold. Mansa Musa must have made quite the impression during his trip with his large entourage and massive display of wealth. During his travels, Mansa Musa gave away and spent a significant amount of gold, but he also brought back a lot of new ideas to Mali. This included a number of scholars such as architects, poets, and teachers who helped to improve his empire.
However, by way of archaeological and anthropological discoveries, we continue to learn how far back and deep into sub-sahara Africa the genesis of advanced human civilization dates. Incredible as it seems, thousands and thousands of years before Nile Valley civilizations there were the Lebomba Bone and Ishango Bone.
The Lebombo bone is one of the oldest mathematical artifacts known, a small piece of the fibula of a baboon, found near Border Cave in the Lebombo Mountains between South Africa and Swaziland. Discovered in the 1970s during excavations of Border Cave and dated about 35,000 B.C., the Lebombo bone is marked with 29 clearly defined notches. This suggests it may have been used as a lunar phase counter, in which case African women may have been the first mathematicians since keeping track of menstrual cycles requires a lunar calendar. Certainly, the Lebombo bone resembles calendar sticks still used by Bushmen in Namibia. source