WEBSTER-ASHBURTON TREATY. The Webster-Ashburton Treaty resolved many disputed issues in British-American relations during the mid-nineteenth century. Of these, boundary disputes were the most prominent. After the War of 1812, the United States complained that Britain still habitually violated American sovereignty. The dispute over the northeastern boundary, between Maine and New Brunswick, Canada, had brought nationals of the two countries to the verge of armed hostility. This was settled by the treaty through what then appeared to be a wise compromise of territorial claims, which provided the present-day boundary line. (It was a concession that knowledge of Benjamin Franklin's Red-Line Map, not made public until 1932, would have made unnecessary, because the boundary had already been drawn.) The treaty also rectified the U.S.-Canada boundary at the head of the Connecticut River, at the north end of Lake Champlain, in the Detroit River, and at the head of Lake Superior. A useful extradition article and another providing for the free navigation of the St. John River were included in the treaty. Exchanges of notes covering the slave trade ensured the United States protection against "officious interference with American vessels" and the protection of "regularly-documented ships" known by the flag they flew.
Samuel FlaggBemis/a. g.