Formal, binding written agreement entered into by the United Kingdom and the United States in international law
Established the 49th parallel as the US-UK boundary and set joint occupation of the Oregon Country, shaping North American territorial borders.
Key Facts
- Signed
- 20 October 1818
- Boundary established
- 49th parallel north
- Region jointly occupied
- Oregon Country (Columbia District)
- British territory ceded
- Rupert's Land south of 49th parallel, east of Continental Divide
- US territory ceded
- Northernmost Missouri Territory north of 49th parallel
- Also known as
- Anglo-American Convention of 1818 / London Convention
By the Numbers
Location
Cause → Event → Consequence
Following the War of 1812, the United States and the United Kingdom faced unresolved disputes over fishing rights, the boundary between their North American territories, and competing claims to the Oregon Country. Both nations sought a stable, surveyor-friendly demarcation to replace the earlier watershed-based boundaries and to prevent further conflict over their shared continental frontier.
On 20 October 1818, negotiators for the United States and the United Kingdom signed the Convention in London. The agreement fixed the international boundary along the 49th parallel north from the Lake of the Woods to the Rocky Mountains, granted American fishing rights off Newfoundland and Labrador, and established a ten-year joint occupation of the disputed Oregon Country, deferring a final settlement of that region.
Britain ceded all of Rupert's Land south of the 49th parallel and east of the Continental Divide, including the southern portion of the Red River Colony, marking its last permanent major territorial loss in the continental United States. The United States in turn ceded the northernmost edge of the Missouri Territory, its first significant North American cession to a foreign power. Joint occupation of the Oregon Country continued until the Oregon Treaty of 1846 resolved that question.
Political Outcome
Boundary fixed along 49th parallel; joint occupation of Oregon Country established; fishing rights granted to the US off British North America.
Contested and ambiguous borders between US and British North America following the War of 1812
49th parallel recognized as the fixed boundary east of the Rockies; Oregon Country under agreed joint occupation