The Great West Point Chain https://allthingslib...st-point-chain/
The Hudson River Chain refers to two chain booms and two chevaux de frise constructed from 1776 to 1778 during the American Revolutionary War across the Hudson River as defenses to prevent British naval vessels from sailing upriver. These defenses along the Hudson River were overseen by the Highlands Department of the Continental Army. The most significant and successful was the Great Chain, constructed from West Point in 1778, and used through 1782 after the war's end. The huge links for the chains were forged at iron works in Orange County, New York.
Francis Bannerman's surplus "had links from the famous iron chain that had been strung across the Hudson River during the American Revolution as a device to snag British ships. The links were cut into cross sections a quarter of an inch thick, polished bright, stamped “Section of chain used by General George Washington, West Point, New York, 1778.” The last of these links to the Revolution were sold in the 1940’s for $2.75 apiece."