You know what I am going to take the plunge and actually TRY to design a setting (or pieces of a setting) based entirely off African history and African nations... HOPEFULLY ignoring the whole White Slavery thing MOSTLY (mostly because... that is so cliché that not doing it actually gives you originality points)
Africa is so fascinating and yet I learned almost NOTHING about it other than "White people enslaved Africans here be" (Though... a group of people who start and end as victims with little-no other defining features is typical school history affair... Like Women's history!)
Not a lot of the culture that used to be there survived because none of it was written down. A funny thing about, for instance, the Congo region is that the first attestation of it in history is on a marker denoting the purchase of a Pygmy slave, purportedly from the land of the walking spirits, and the gratitude of a pharaoh for the exotic nature of the slave in question.
What doesn't help is that after starting to more intently interfere in native political entities the Europeans proceeded to fuck up the ethnography of the area, which they then fed back to the populace as stereotypes through the school system in the late 19th-early 20th century.
The Kingdom of Kongo is a fun one, being a Bantu kingdom whose kings became Christianized through exposure and trade with the Portuguese (to the point of one prince becoming the first black bishop in the Catholic Church before tragically succumbing to illness).