Webster-Ashburton Treaty, Aug., 1842, agreement concluded by the United States, represented by Secretary of State Daniel Webster, and Great Britain, represented by Alexander Baring, 1st Baron Ashburton. The treaty settled the Northeast Boundary Dispute Northeast Boundary Dispute, controversy between the United States and Great Britain concerning the Maine–New Brunswick boundary. The treaty of 1783 ending the American Revolution had described the northeastern boundary of the United States as running due north
..... Click the link for more information. , which had caused serious conflicts, such as the Aroostook War Aroostook War, Feb.–May, 1839, border conflict between the United States and Canada. In 1838, Maine and New Brunswick both claimed territory left undetermined on the U.S.-Canadian border, including the valley of the Aroostook River.
..... Click the link for more information. . Over 7,000 sq mi (18,100 sq km) of the disputed area, including the Aroostook valley, were given to the United States, and several waterways, including the St. Johns River, were opened to free navigation by both countries. The Webster-Ashburton Treaty also settled the disputed position of the U.S.-Canada border in the Great Lakes region. Other clauses provided for cooperation in the suppression of the slave trade and for mutual extradition of criminals. Some disputes between the United States and Britain, notably the one concerning the Oregon boundary, were ignored. The treaty, however, served as a precedent in peaceful settlements of disputes between the two countries.

Bibliography

See H. S. Burrage, Maine in the Northeastern Boundary Dispute (1919) and H. Jones, To the Webster-Ashburton Treaty (1977).

Webster-Ashburton Treaty

(1842) Treaty between the U.S. and Britain establishing the northeastern boundary of the U.S. Negotiated by U.S. secretary of state Daniel Webster and Britain's ambassador Lord Ashburton, it also provided for Anglo-U.S. cooperation in the suppression of the slave trade. It fixed the present boundary between Maine and New Brunswick, granted the U.S. navigation rights on the St. John River, provided for extradition in nonpolitical criminal cases, and established a joint naval system for suppressing the slave trade off the African coast.