The slave trade indicated that a total of about ten million human beings were exported from Africa to the New World in the 220 years between 1650 and 1870, which were the high point of the trade. So as a sum up the population of Africa stood still for the 150 years between 1650 and 1800 before beginning to rise again as it has continued to do until the present.
In the region of West Africa the slave trade had been the major occupation of Europeans and their African collaborators for centuries. The slaves were banned by acts of parliament form the British. In this region the slave trade was replaced by a new economy on agricultural exports from Africa and imports of Europe and governments had somewhat different goals for their colonies and administered them in different ways arrived at by necessity and experiment rather than by plan.
From the early 19th century, the French were the leading European influence in West Africa. This is where the slave trade began. The West Africans were able to be at advantage over the other regions because they became active partners with the whites in securing supplies. In some West African states, the West African Leaders would trade slaves for firearms, which they used to get more slaves. The slaving center moved southward into the Portuguese colony of Angola.