Description: The United States Corps of Engineers began building Fort Montgomery in 1816, after the War of 1812. It was sited near Rouses Point, New York, at the northern end of Lake Champlain at the mouth of the Richelieu River. In the case of another war, it was to guard the northern American border against British and Canadian incursions and provide a base for United States armies invading Canada in that area. However, construction had to be abandoned after two years when the fort was found to be slightly inside Canada's boundaries. Fort Montgomery got the nickname 'Fort Blunder' and was never completed. The site later reverted to the United States in 1842 as a good will gesture between Britain, Canada and the United States, nations that have since been allies in the great struggles of the 20th century.