Why did coastal cities become wealthy

Boats and ships could easily reach them and they had access to fish and seafood to sell but mostly they could easily trade with other cities and civilizations

The  pan-african movement  was an "emotional, cultural, psychological and ideological  movement  that began among the  african  dispora in the western hemisphere, for a closer  purpose, so that  african  people could feel secure, attain political, economic as well as psychological power visa vis other races or world regions" .