With the exception of South Africa, with a climate much more like Europe, there were basically no white colonists in Africa until after the continent was divided among the European powers throughout the middle and later 19th century. Even then, the number of white colonists was small, and even in South Africa significantly outnumbered by the locals at all times not just early on. Most of Africa was known, with good reason, as "the white mans' grave". Tropical diseases killed off a high percentage of all white imports, and in some areas much of imported livestock including the major "prime mover" - horses. Later on you had tobacco and cotton, as well as other crops grown in areas that were conducive to their cultivation. This, by the way, was much more in East Africa as opposed to West Africa which was where most slaves came from (and the earliest western exploration).
From the 1600's when the African slave trade began, until the early 19th century when the international slave trade was suppressed slave raised rice, indigo, tobacco, and cotton from North America was a huge economic impact. During that same time farmed crops from Africa, as opposed to gathered crops done by locals, were minimal and even natural crops from Africa were quite limited. Gold, ivory, "black ivory" (slaves), and various exotic goods consisted the products of sub-Saharan Africa during this time.
From the 1600's when the African slave trade began, until the early 19th century when the international slave trade was suppressed slave raised rice, indigo, tobacco, and cotton from North America was a huge economic impact. During that same time farmed crops from Africa, as opposed to gathered crops done by locals, were minimal and even natural crops from Africa were quite limited. Gold, ivory, "black ivory" (slaves), and various exotic goods consisted the products of sub-Saharan Africa during this time.