The Convention of 1818 ran the boundary along the 49th parallel to the Rocky Mountains and left Oregon Country, the Hudson's Bay Company's Columbia District, under joint occupation. The cry "Fifty-four Forty or Fight" ran to 54 degrees 40 minutes, the southern limit of Russian America in 1824-1825. The Mexican-American War began in April 1846. On 12 June the Senate voted 38 to 12 that Polk accept the British offer to negotiate. The treaty for the settlement of the Oregon boundary was signed at Washington on 15 June 1846. James Buchanan, secretary of state. Richard Pakenham, British envoy. In London, Aberdeen.

Article I: from the point on the 49th parallel where existing treaties terminate, the line continues westward along that parallel to the middle of the channel which separates the continent from Vancouver's Island; thence southerly through the middle of the said channel and of Fuca's Straits to the Pacific Ocean. Navigation of the whole of the said channel and straits south of the 49th parallel remains free and open to both parties. Vancouver Island remains British. Point Roberts, a southern tip of a Canadian peninsula, still falls south of 49 and becomes an American exclave.

Article II: from the intersection of the 49th parallel with the great northern branch of the Columbia, navigation is free to the Hudson's Bay Company and British subjects to the ocean, with the usual portages. Article III: the possessory rights of the Company and of British subjects already occupying land south of 49 shall be respected. Article IV: the farms of the Puget's Sound Agricultural Company, north of the Columbia, are confirmed; the United States may obtain them at a proper valuation.

Article V: ratifications by the President, by and with the advice and consent of the Senate, and by Her Britannic Majesty; exchange at London within six months. The exchange: 17 July, Louis McLane and Palmerston. Polk proclaimed the treaty on 5 August. Oregon Territory, 15 August 1848. The phrase "middle of the channel" left the San Juans in dispute; the Pig War, 1859; arbitrator Wilhelm I, 21 October 1872, chose Haro, not Rosario, under the Treaty of Washington of 1871.

This is not the Convention of 1818, and not Webster-Ashburton of 1842. The cover is the signature page, with the seals of Buchanan and Pakenham.

Sources: Oregon Treaty; Treaty between Her Majesty and the United States of America, for the Settlement of the Oregon Boundary.