When the war between the United States and Great Britain, known as the War of 1812, ended after the Treaty of Ghent was signed, then-President James Madison decided to build a Fort at the Canada–US border of Lake Champlain to prevent future invasion and keep Canada out. That was a sound idea, except there was one issue. The fort was built in Canada.

War of 1812

The War of 1812 originated from the British’s opposition to US trade and their desire to expand its territory in North America. In 1807, the Royal Navy implemented tighter restrictions on American trade with France. And so, The US Congress declared war in 1812. The Native Americans were also unhappy about America’s expansion, and so they sided with the British, although some sided with the Americans. The war ended with Peace talks between Britain and the US in 1814, and the Treaty of Ghent was signed. However, one British general led an assault on New Orleans after, unaware of the said treaty.

Construction of Fort Blunder

To protect against an attack from British Canada, construction of the octagonal structure with 30 feet walls began in 1816. Two years after the beginning of the construction, then-President James Monroe visited it and the military reservation adjacent to it, only to find that a surveying error caused them to build their fortification in the Canadian land.

“Fort Blunder” (Fort Lennox) Isle aux Noix, Lake Champlain, Quebec (Wikimedia Commons).

The new survey revealed that the 45th parallel north was actually located around 1.2 km south. Thus, their construction falls on the Canadian border. Now, that’s some expensive mistake.