On the death of her father, Southern belle Yvonne DeCarlo finds out that her mother was one of her father’s slaves. That makes her his property too, and therefore is sold as part of his estate. She’s thrown in with a bunch of African slaves and put up for auction, before she’s rescued by Clark Gable for $5000.
This is the “passing-for-white woman in slavery” device, used in stories as diverse as Clotel and The Memoirs of Dolly Morton. It’s inherently dramatic and lends itself to both drama and erotica, as the protagonist is suddenly stripped of everything and thrown into a new realm, a transition between two different sexual economies.
The recurring figure of the beautiful woman who is both black and white, a highly liminal figure, has some troubling issues: it suggests that we (the presumably white audience) can only see how bad slavery is when it happens to a (passing for) white woman, who isn’t “tough” like a black woman. This is one of the many points of slippage between abolitionist media and exploitation.