Fort Montgomery: Built on the Wrong Side of the Border

Near Rouses Point, at the northernmost tip of Lake Champlain, there is a ruined masonry fort with an embarrassing origin story.

After the War of eighteen twelve exposed how vulnerable the northern border was, the United States began building a large fortification here in eighteen sixteen to guard the lake approach from Canada. Workers cut stone, hauled timber, and laid foundations for years. Then the surveyors noticed something catastrophic: the site was in Canada. The entire project sat on the wrong side of the boundary line.

Construction stopped. The half-built fort was abandoned and became known in the press as Fort Blunder. After the Webster-Ashburton Treaty of eighteen forty-two finally settled this section of the border, the United States built a second fort on the correct ground in eighteen forty-four and named it Fort Montgomery, after a Revolutionary War general. The second fort also went largely unfinished, rendered obsolete by changes in military technology before it was ever manned in anger. Today the ruins sit near the border crossing, a monument to the difficulty of knowing exactly where one country ends and another begins.