Answer:
Sixteenth to mid-nineteenth centuries promoted West African state building and expansion.
Explanation:
A range of important trading kingdoms developed in West Africa. The West African kingdoms dominated significant maritime trade routes that joined North Africa and West Africa.
Starting in the Trans-Saharan commerce, West Africa was rich in gold while North Africa was rich in the salt that West Africa required, the trans-Saharan trade led to a transfer of Gold and Salt.
