Answer:
The slave trade had devastating effects in Africa. Economic incentives for warlords and tribes to engage in the slave trade promoted an atmosphere of lawlessness and violence. Depopulation and a continuing fear of captivity made economic and agricultural development almost impossible.
European slavers usually left behind or killed persons who were elderly, disabled, or sick since they were too weak to provide for themselves or be in any workforce. In the end, the slave trade left the continent underdeveloped, disorganized, and vulnerable to the next phase of European hegemony colonialism.