Fort Montgomery on Lake Champlain is the second of two American forts built at the northernmost point of the American part of the lake: a first, unnamed fort built on the same site in 1816 and Fort Montgomery built in 1844.The current massive stone fortification, the second fort, was built between 1844 and 1871 at the U.S.-Canada border of Lake Champlain at Island Point in the village of Rouses Point, New York.