"High Plains (U.S.)" . . "High Plains (U.S.) History 19th century." . . "Great Britain" . . "Canada Relations United States." . . "Northern boundary of the United States" . . "Canada" . . "Geschichte 1872-1874" . . . . . . "Electronic books"@en . . . . . . "The border between Canada and the United States- the longest undefended border in the world-was laid out in many stages over more than a century, but the biggest part of the job was the long, (mostly) straight line across the prairies. On September 18, 1872, a full five years after confederation, two large teams of army surveyors-one from each country-met at the Red River on the Manitoba-Minnesota border. They were there to fix, for the first time, the precise location of the 49th Parallel between the swampy shores of the Lake of the Woods-where the border had an awkward, keyhole-shaped n."@en . . . "History" . "History"@en . . . . . . . . . . . . . . . . . . "Arc of the medicine line : mapping the world's longest undefended border across the western plains"@en . . . . . . . . . . . "Arc of the Medicine Line mapping the world's longest undefended border across the western plains"@en . . "Biography" . . . . . . . . . . . "Arc of the Medicine Line : mapping the world's longest undefended border across the western plains" . . . . . . . . . . . . . . . . . . . "Géomètres Canada Biographies." . . "Nord-Ouest canadien" . . "Great Britain Relations United States." . . "SCIENCE Earth Sciences Geography." . . "Northern boundary of the United States History 19th century." . . "Astronomie États-Unis 19e siècle." . . "Vermessung." . . "Northwest, Canadian" . . . . "Kartographie." . . "Astronomy Northern boundary of the United States History 19th century." . . "Cartography Northern boundary of the United States History 19th century." . . "Vie des pionniers Hautes Plaines (États-Unis)" . . "Vie des pionniers Hautes plaines (États-Unis)" . "United States" . . "Astronomie Frontière du Nord (États-Unis) Histoire 19e siècle." . . "United States Relations Great Britain." . . "Cartographie Frontière du Nord (États-Unis) Histoire 19e siècle." . . "United States Relations Canada." . . "Indiens d'Amérique États-Unis Relations avec l'État Histoire 19e siècle." . . "Kanada." . . "États-Unis" . . "Cartographie Amérique du Nord Histoire 19e siècle." . . "Frontière du Nord (États-Unis)" . . "Indians of North America Government relations History 19th century." . . "Grenze." . . "Géomètres États-Unis Biographies." . . "Astronomie Amérique du Nord Histoire 19e siècle." . . "Grande-Bretagne" . . "Frontier and pioneer life High Plains (U.S.)" . . "1800 - 1899" . . "Great Plains." . . "Hautes Plaines (États-Unis)" . . "Hautes plaines (États-Unis)" . "USA." . . "Cartographie États-Unis 19e siècle." . .