How did slavery affect Africa socially, economically and politically?

Between the fifteenth and nineteenth centuries, an estimated 12 million Africans were enslaved and transported across the Atlantic Ocean. Socially, this process had a dramatic impact on Africa's population because it removed a huge number of men and women. By 1850, for example, the population of Africa was 25 million people but historians believe that it would have been double this number, had slavery not taken place. 

For those left behind, slavery had important economic consequences too. Because so many able-bodied men and women were transported abroad, Africa did not have enough workers and entrepreneurs to bring about an agrarian revolution and, in the longer-term, to industrialise. A number of Africans turned instead to working in the lucrative slave-trade and this created important political consequences because traders found it harder to enslave people during peace time. Slave traders, therefore, created political rifts and conflicts to ensure a steady supply of prisoners of war who could be sold into slavery. In Ghana, for example, the rise of slavery coincided with the introduction of gunpowder and explosives to the country.