During the second half of the nineteenth century and proceeding through the end of the First World War, European imperialism in Africa significantly altered much of the continent, both for better and for worse. Perhaps the most striking change wrought by imperialism in Africa during World War I was the increase in resources imperialist nations enjoyed. In a war that proved as devastating as World War I did, a sizeable pool of resources, including manpower, was essential. This fact negatively impacted the continent in that this use of resources often turned into an abuse of resources. Thinking only of the economic, political, and military advantages resulting from the possession of colonies in Africa meant imperialist nations often overlooked the welfare of the colonies themselves. In addition, the presence of Europeans also meant the presence of European diseases, against which Africans had no real defense. The most negative aspect of European imperialism in Africa is that it often meant the breakdown of traditional African cultures, either obscuring or obliterating their cultural identity.
This being said, one positive that arose from European imperialist expansion in Africa was that the harvesting of resources in African nations did not stop when Europeans left. Imperialism in Africa provided those nations with an awareness of the commodities which they possessed, allowing them to continue to take advantage of them. In terms of agriculture, Africans could continue to develop system of agriculture begun by Europeans.
Politically, imperialism in Africa has generally had a positive effect, providing models (infrastructure) for government that would continue even after the African nations began to govern themselves. One notable exception is South Africa, which existed under apartheid, the system of segregation that remained in place there until very recently. When European nations began leaving Africa, they often left power vacuums, which opened the door for dictatorships in the same vein as Idi Amin in Uganda.