Explain the contributions that lead to the success of mali

Ghana, Mali, and Songhai were three of the greatest western African trading states. Beginning with Ghana as early as 300 c.e. and ending with the conquest of the Songhai by Morocco in the 16th century c.e., they dominated the trade of gold, salt, and merchandise between North Africa and sub-Saharan Africa. Arab scholars and merchants as far away as Baghdad marveled at the wealth of these African states.  Hope this helps