To or in prison, as in They sent him up the river for five years. This phrase originally referred to Sing-Sing Prison, on the Hudson River about 30 miles north of New York City. So used from about 1890 on, it was broadened to apply to any prison by the early 1900s.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
How to use up the river in a sentence
“Why, this might be an up-the-river jaunt,” said Denham, as the appetising daintiness of each article of food revealed itself.Forging the Blades | Bertram Mitford