What is the theme in Cane River by Lalita Tademy?

The importance of family is a central theme of this story, made more important to the families that are torn apart when slaves are sold off. This is clearly seen when the slaves of Rosedew are about to be auctioned. As they are being "assessed" prior to the auction, the men and women are fearful and stand clustered in family groups. As they are forced to break up from these groups and line up, it's Suzette's father who explains repeatedly that they will be free to return to their families after the assessors have finished their work.