sell down the river


Betray, as in They kept the merger a secret until the last minute, so the employees who were laid off felt they'd been sold down the river. This expression, dating from the mid-1800s, alludes to slaves being sold down the Mississippi River to work as laborers on cotton plantations. Its figurative use dates from the late 1800s.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.