To betray. This term arose in the mid-nineteenth-century United States and referred to selling slaves down the Mississippi River, where they would almost certainly be worked to death in the cotton fields. The term was used in its literal sense by Harriet Beecher Stowe in her best-selling novel Uncle Tom’s Cabin, but by the late nineteenth century it was being used figuratively. P. G. Wodehouse used it in Small Bachelor (1927): “When Sigisbee Waddington married for the second time, he to all intents and purposes sold himself down the river.”