The economist Thomas Sowell is said to have made a point similar to that of Will Schryver's Mr. Franklin: On a national radio talk show, a caller accused him of denying that slavery had had any real impact on American blacks. "Oh, I don't deny that at all," Professor Sowell responded. "If it weren't for slavery, you and I would likely be living in some Third World African hell hole."
The reason Africa is a "Third world hell hole" has an awful lot to do with Imperialism, not through the fault of the people who lived in Africa. Those same imperialists are the ones who were selling Africans into slavery. In essence, Thomas Sowell is grateful that his ancestors were sold into slavery, because otherwise he would have grown up in the ruins that the slavers left Africa in. Bizarre.
Most of the political problems of modern Africa are connected with the fact that 19th century European powers sliced up Africa into large and fairly arbitrary colonial chunks that brought together peoples who often had nothing in common culturally, historically, or even linguistically. Nigeria is a pretty good example.
Then, under the pressure of anti-colonialist movements in the second half of the 20th century, they abandoned these pseudo-countries to the rule of tiny and immature political classes that soon morphed into dictatorships, exploitative oligarchies, or in some cases pure chaos. Outside powers were of course ready to sell arms to such regimes, buy diamonds mined by effective slaves, and prop up their favorite dictators until they became inconvenient.