I see that the theme of slavery, or racial issues, runs through all your choices. With that in mind, have a look at:
The Invention of Wings, also by Sue Monk Kidd, the author of The Secret Life of Bees, is even better IMO. And interesting because based loosely upon a true story of two sisters who campaigned persistently against slavery although born into a plantation family.
The Last Runaway by Tracy Chevalier, and A Respectable Trade by Philippa Gregory are very readable if a little bit sanitised.
More challenging, and probably a better book, is The Long Song, by Andrea Levy. The cadences of the language take a little bit of getting used to but I think the narrative style works very well.
There's the famous Roots by Alex Haley - a long time since I read it - and another big read, Sacred Hunger by Barry Unsworth, which I found engrossing first time round and am planning to reread soon.