18181776 Club
A ruler-straight line settles the border: the 49th parallel runs to the Rockies
Britain gives up land south of the line and the US gives up a sliver near the Milk River, leaving the plains with an easy boundary to survey.
For thirty-five years, the US-Canada border had rested on a line from the 1783 Treaty of Paris that ran to the Mississippi from Lake of the Woods, a route no accurate map could confirm. On October 20, 1818, American negotiators Albert Gallatin and Richard Rush signed the Convention of 1818 with Britain's Frederick John Robinson and Henry Goulburn in London, fixing the boundary along the 49th parallel from Lake of the Woods to the Rocky Mountains. Britain ceded territory covering parts of present-day Minnesota, North Dakota, and South Dakota; the US gave up a small strip north of the line near the Milk River. The treaty also opened the Oregon Country to joint occupation for ten years…
