Harvard Africa Map
This is a new Harvard Africa Map that allows for layering of different maps and geospatial materials from different collections. In this screenshot, I have layered two historical maps over the Google Map layer. You can even adjust the density of the maps off to the right. Quite a fun way to explore older data and a very promising creation.
You can find the beta site at http://cga-3.hmdc.harvard.edu/africamap/. Give it a whirl and enjoy.
The Africa map clearly defines the geographical and political boundaries of the continent. The map of Africa also plots the major rivers, deserts, climatic conditions and natural vegetation of the continent.