49th parallel north

From Wikipedia, the free encyclopedia.

The 49th parallel of north latitude forms part of the international boundary between Canada and the United States from Manitoba to British Columbia on the Canadian side and from Minnesota to Washington on the U.S. side. Its use as a border is a result of the Anglo-American Convention of 1818 and the Oregon Treaty of 1846.

After the United States acquired the Louisiana Purchase in 1803, it was generally agreed that the boundary between it and British Rupert's Land was along the watershed between the Missouri River and Mississippi River basins on one side and the Hudson Bay basin on the other. However, it is difficult to precisely determine the location of a watershed in a region of level plains, such as in central North America. The British and American committees that met after the War of 1812 to resolve boundary disputes recognized there would be much animosity in surveying the watershed boundary, and agreed on a simpler solution in 1818: the 49th parallel. Both sides gained and lost some territory by this convention, but the United States gained more than it lost, in particular securing title to the Red River Basin. This convention established the boundary only between the Lake of the Woods and the Rocky Mountains; west of the Rockies, the convention established joint occupation of the Oregon Country by both parties. A geographical oversight resulted in the creation of the Northwest Angle.

Although the Convention of 1818 settled the boundary from the point of view of the non-Aboriginal powers, neither the United Kingdom nor the United States was immediately sovereign over the territories on its side of the line: effective control still rested with the local nations, mainly the Métis, Assiniboine, Lakota and Blackfoot. Their sovereignty was gradually ceded by conquest and treaty during the several decades that followed. Among these nations, the 49th parallel was nicknamed the Medicine Line because of its seemingly magical ability to prevent U.S. soldiers from crossing it.

In 1844, part of James K. Polk's platform in his presidential run was that the northern border of the Oregon Territory should be 54°40′; he even had a campaign slogan of "Fifty-Four Forty or Fight". However, with the Mexican-American war starting in 1846, the military was needed elsewhere and this goal was not achieved.

In 1846 the Oregon Treaty divided the Oregon Country between British North America and the United States by extending the 49th parallel boundary to the west coast, ending at the Strait of Georgia; it then circumvents Vancouver Island through the Strait of Juan de Fuca. This had the side-effect of isolating Point Roberts, Washington.

Although parts of Vancouver Island and much of Eastern Canada are located south of the 49th parallel, and parts of the United States (Alaska, Northwest Angle) are located north of it, the term 49th parallel is sometimes used as a nickname for the entire Canada-U.S. border. This can be misleading, since many of Canada's most populated regions are well south of the 49th parallel, including the two largest cities Toronto (44° north) and Montreal (46° north) and the capital Ottawa (45° north) —as are the three Maritime provinces.

Parts of the 49th parallel were originally surveyed using astronomical techniques that did not take into account slight departures of the Earth's shape from a simple ellipsoid, and the surveys were subject to the limitations of early to mid 19th-century technology. As a result, in some places, the surveyed 49th parallel is as much as several hundred feet from the actual geographical 49th parallel for the currently adopted datum, WGS84. The Digital Chart of the World (DCW), which uses the Clarke 1866 ellipsoid, reports the border on average at latitude 48° 59′ 51″ north, roughly 270 m (290 yd) south of the modern 49th parallel. It ranges between 48° 59′ 25″ and 49° 0′ 10″ north, respectively 810 m (885 yd) and 590 m (645 yd) on either side of the average. In any case, the Earth's North Pole moves around slightly, notionally moving the 49th and other parallels with it - see polar motion.

While the United States and Canada have not disputed the boundary from the original survey lines, the difference of the survey from the geographical 49th parallel was argued in front of the Washington Supreme Court in the case of State of Washington v. Norman, under the premise that Washington did not properly incorporate the portions of land north of the geographical 49th parallel, as laid out by detailed GPS surveying. The court decided against the premise, ruling that the internationally surveyed boundary also served as the state boundary, regardless of its actual position.

[edit]