Final answer:
The 49th parallel between the United States and Canada is a geographical boundary established by the Treaty of 1818 and confirmed by the Oregon Treaty of 1846.
Step-by-step explanation:
The 49th parallel between the United States and Canada is a geographical boundary. It was established as part of the Treaty of 1818 and later confirmed by the Oregon Treaty of 1846. This boundary divides the two countries along the line of latitude at 49°N, running from Washington state to the Canadian province of British Columbia.
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