An agreement between Britain and the USA settling the present Maine–New Brunswick border. Negotiated by the US Secretary of State Daniel Webster (1782–1852) and the British minister Lord Ashburton, the treaty settled the disputed boundaries in the north‐east, awarding the USA more than 18,000 sq km (7000 sq miles) of the 31,000 sq km (12,000 sq miles) disputed area and opening the St John River to free navigation. The treaty also fixed the Canadian–US boundary in the Great Lakes region and served as a precedent for the successful settlement of other 19th‐century border disputes between Britain and the USA.