during the Columbian Exchange, four countries (Europe, Africa, Asia and the Americas) traded goods such as: Disease, tobacco, enslaved Africans, ideas, technology, weapons, gold silver, pigs, sheep, cattle chickens and horses.
Yes. The Europeans just had to make contact with the Muslim Arab slave traders. The Muslims where more than happy to supply all the black africans that the Europeans wanted in exchange for gold and weapons.
Most Africans living south of the Sahara are black. The bushmen of southern Africa are not black but more brown. The Arabs of the east coast are not black. The Europeans living in South Africa are not Black.