Governments of the United States and the United Kingdom, Oregon Treaty (1846)
“ From the point on the forty-ninth parallel of north latitude where the boundary laid down in existing treaties and conventions between the United States and Great Britain terminates, the line of boundary between the territories of the United States and those of her Britannic Majesty shall be continued westward along the said forty-ninth parallel of north latitude to the middle of the channel which separates the continent from Vancouver's Island ”
