Fort Montgomery, New York

This northwestern arm of Lake Champlain transitions here into the Richelieu River, which flows into the St. Lawrence River, near Montreal. The river is a significant historic route connecting the US and Canada, a pathway for troops during skirmishes between the two nations, which is why the Americans established a fort here, on the New York side, as early as 1816, to defend the US from British Canada. It was later discovered that, due to a surveying error, the 45^th Parallel, and thus the US/Canada border, was three quarters of a mile south of the fort, which put the fort in Canada. It became known as Fort Blunder. With the signing of the Webster-Ashburton Treaty in 1842, which set the boundary through the region as the 45^th Parallel, as previously surveyed, the boundary moved back to the former, incorrect 45^th, and the fort thus became part of the US again. A new and better fort, now called Fort Montgomery, was built at the site from 1844 to 1871, though it never saw battle, and it was eventually decommissioned. Much of its cut stone walls were ground up for aggregate to build a bridge that now crosses the lake, near the fort. The fort and the land around it is in private hands, and has been on the market for years, with plans to build a housing complex and a marina.