By AD100 farming village in the west Africa were growing in to town. By AD800 the rulers of the Sonnnie people has united many farming villages to create the kingdom of Ghana. Ghana became the part of important trade network. Gold was located in the broad "v" made by the Niger and Senegal rivers. The king controlled gold-salt trade routes across west Africa by collecting tolls.
https://answers.yahoo.com/question/index;_ylt=AwrVk9zpE8Zby0IAN54PxQt.;_ylu=X3oDMTByYnR1Zmd1BGNvbG8DZ3ExBHBvcwMyBHZ0aWQDBHNlYwNzcg--?qid=20120205185418AAbUbs4&p=How%20did%20the%20goat%20salt%20trade%20affect%20the%20kingdom%20of%20Ghana
