The White House published on 21 September 2016 a fact sheet titled "U.S.-Africa Cooperation on Trade and Investment Under the Obama Administration."
This document offers a good summary of U.S. programs and efforts to increase trade and investment with Africa. U.S. investment in Africa has increased impressively from a total of $37 billion in 2008 to $64 billion in 2015. Trade, on the other hand, has dropped sharply from $142 billion in 2008 to $52 billion in 2015. Most of the decline is accounted for as a result of reduced oil imports from Africa following fracking in the United States.