7 Influential African Empires - History Lists
This might also be worth a look.
8 Successful and Aspiring Black Communities Destroyed by White Neighbors
On the issue of racism and the success of a group this is also very interesting about the Osage Indians, oil discoveries of reservation land and systematic murder of many of these Osage by whites and other Osage.
Book review: 'Killers of the Flower Moon' examines the Osage murders in 1920s Oklahoma | News OK