Europeans were anxious to acquire gold in Africa because there was a pressing need for gold coin within the growing capitalist money economy. Since gold was limited to very small areas of Africa as far as Europeans were then aware, the principal export was human beings. Only in a very few places at given times was the export of another commodity of equal or greater importance. For instance, in the Senegal there was gum, in Sierra Leone camwood, and in Mozambique ivory. However, even after taking those things into account, one can say thatEurope allocated to Africa the role of supplier of human captives to be used as slaves in various parts of the world.When Europeans reached the Americas, they recognised its enormous potential in gold and silver and tropical produce. But that potential could not be made a reality without adequate labour supplies. The indigenous Indian population could not withstand new European diseases such as small-pox, nor could they bear the organised toil of slave plantations and slave mines, having barely emerged from the hunting stage. That is why in islands like Cuba and Hispaniola, the local Indian population was virtually wiped out by the white invaders. At the same time, Europe itself had a very small population and could not afford to release the labour required to tap the wealth of the Americas. Therefore, they turned to the nearest continent, Africa, which incidentally had a population accustomed to settled agriculture and disciplined labour in many spheres. Those were the objective conditions lying behind the start of the European slave trade, and those are the reasons why the capitalist class in Europe used their control of international trade to ensure that Africa specialised in exporting captives (Source: How Europe Underdevloped Africa).