sell down the river

Meaning

Verb

• To betray, especially in a manner which causes serious difficulty for the one betrayed.

Origin

• Probably from the practice in the U.S., prior to the American Civil War, of trading in slaves who were transported via the Mississippi River:
• :* 1885, Mark Twain, Huckleberry Finn, ch. 42:
• :*: "[H]e ain't no slave. . . . Old Miss Watson died two months ago, and she was ashamed she ever was going to sell him down the river, and said so; and she set him free in her will."