Although the idea, and the fact, of being sold "DOWN THE RIVER" drives the novel's narrative, this is its only illustration of a slave auction, and it illustrates a hypothetical one. Roxy is offering to let her son sell her in order to raise money to pay his gambling debts, even though (as he reminds her) she is free. "Much diff'rence dat make!" she replies; "White folks ain't partic'lar. De law kin sell me now if dey tell me to leave the State in six months and I don't go."
(I wonder if contemporary readers would have recognized the black man with Roxy here as "Uncle Tom," who was invariably played as an old man in the "Tom Shows" that were still extremely popular when the novel appeared.)
The Barrett Collection, UVA PS 1317 .A1 1894