The Economic Community of West African States (ECOWAS) was created by the Treaty of Lagos in Lagos, Nigeria, on 28 May 1975. It was created to promote economic trade, national cooperation, and monetary union, for growth and development throughout West Africa.
There are currently 15 member countries in the Economic Community of West African States. The founding members of ECOWAS were:
Burkina Faso (which joined as Upper Volta).
Mauritania (left 2002),
Cape Verde joined in 1977.