How can you not mention Kehinde Wiley who did the official portrait of President Obama? His classical representations of black Americans in oil paint are incredible, and I have seen them on display at many top art museums. His larger works are selling for well over a half a million dollars. If you want skillful and compelling art by black American artists, you will find plenty if you leave the part of the museum that features European Impressionism and go to part displaying Modern American Art. The cards with the information about each painting don't state the artists race though.

https://artincontext.org/famous-black-painters-and-artworks/