<P> In the western Sahel , the rise of settled communities was largely the result of domestication of millet and sorghum . Archaeology points to sizeable urban populations in West Africa beginning in the 2nd millennium BCE . Symbiotic trade relations developed before the trans - Saharan trade , in response to the opportunities afforded by north - south diversity in ecosystems across deserts , grasslands , and forests . The agriculturists received salt from the desert nomads . The desert nomads acquired meat and other foods from pastoralists and farmers of the grasslands and from fishermen on the Niger River . The forest dwellers provided furs and meat . </P>
what were the two most important commodities traded in early west african civilizations
salt meat and other foods