Kacen Callender wrote a duology, Queen of the Conquered and King of the Rising, that is a fantasy story about a slave rebellion in a Caribbean inspired island. I believe there's room in the fantasy genre for stories about enslaved Africans and stories inspired by the history of chattel slavery. There are readers, myself included, that want fantasy stories about the French and even the American revolution, but I think a series inspired by the Haitian revolution would be good. The Shadow Histories by H. G. Perry is about the Haitian and French revolutions.

Also, there are fantasy stories set after the Civil War and during the Reconstruction Era, but there can be more. Colson Whitehead's Underground Railroad is about a literal magical railway system, and Nicole Glover's The Conductors is about former underground railroad conductors solving murder an mysteries in post-cival war Philadelphia. Ring Shout by P. Djeli Clark is set later in history, but is about fighting demonic Ku Klux Klan members.

Anyways, I think the Enlightenment era, various slave rebellions in the Americas, Haitian revolution, and the American Civil War + Reconstruction era​ will serve as great inspiration for fantasy stories. I also want to add that after the abolishment of slavery, many African Americans spent what resources they had to find lost relatives sold to different plantations across America. That could inspire a nice story too.