What are the effects of slavery on Africa in the past?
In terms of the Trans-Atlantic Slave Trade, the effects were devastating on the history of West Africa. The human toll on slavery was immense. An estimated 11 million Africans died as a result of the slave trade. Some died on the hike to the coast before getting on the ship across the Atlantic, while thousands died en route. Millions died in warfare that resulted from the slave trade within Africa. As a result of this wanton destruction, the population of Africa remained stagnant until the end of the nineteenth century.
The slave trade also changed the political structure of West Africa, which was traditionally decentralized. Powerful predatory kings emerged that were able to broker deals with European powers for slaves. They became more powerful than their neighbors through the import of guns that were exchanged for slaves. This led to more rigid and hierarchal political and social systems in the region.
The slave trade crippled the economic development of the continent. That will happen when you remove millions of young and healthy men from your workforce. Entire villages were left in ruin from the absence of a workforce. All of the energy of many African cultures was focused on defending themselves from capture. Technology and economic development suffered as a result.
Another result of the Atlantic Slave Trade was it permitted European powers to intervene in the political process of West Africa. Europeans did not want strong centralized states in Africa that could challenge their authority and they made attempts to prevent this. When the slave trade was abolished, the continent was grossly underdeveloped, disorganized, and vulnerable to colonization.