By the empires and trading.
The West African trade empires made their money mainly by trading slaves, salt and gold.
trading
It was exloited
Egypt, Sudan & Zimbabwe
Supply and demand
They were centres for transportation and trading.
SonghiGhanaMali
Early empires gained wealth and power by trading slaves, gold, and ivory.
Early empires gained wealth and power by trading slaves, gold, and ivory.
GHANA AND MALI
All of the above; Military, Cultural Conservation, and Trading issues.