This is the first of a two part post on the Oregon Treaty of 1846 and its aftermath.
This week, specifically June 15th, marks an important event in the history of the United States’ changing geography: the 170th anniversary of the signing of the Oregon Treaty. I know, you probably don’t have this event marked on your calendar, but the story of the treaty and its peculiar aftermath represent a fascinating chapter in America’s long history of territorial growing pains. Maps were drawn and scrutinized, diplomats argued for control, and a war was nearly started over…a pig.
In the 1800s, the westward march of American settlers would force many nations with stakes in North America to negotiate the complicated geopolitics of territorial possession. As Carlyn Osborn detailed last December, on the southern and southwestern frontiers of the United States as we know it today, the Adams-Onís Treaty of 1819 separated American and Spanish territories in North America, but borders of control were soon after thrown into turmoil. Mexico’s independence from Spain in 1821, the establishment of the Republic of Texas by American settlers across the Adams-Onís line in 1836, and the annexation of Texas by the United States in 1845 would culminate in the violent conflict of the Mexican-American War. Meanwhile, to the northwest, American border tensions with the British Empire would not spill over into war, in part because of these conflicts to the south. Instead, turbulent but ultimately bloodless negotiations would eventually lead to the signing of the Oregon Treaty.
In 1818, the United States and Great Britain established a boundary between their territories along the 49th parallel (49°N) from Lake of the Woods to the Rocky Mountains, with a peaceful joint occupation declared for the regions to the west of the mountains. The 49th parallel north is a circle of latitude (in the horizontal east-west direction) around the Earth that is 49° north of the Equator. For the area west of the Rockies under joint occupation, the treaty essentially left the hammering out of this international boundary for another day. The borders of this region in political limbo, known to Americans at the time as “Oregon Country,” can be seen in Charles Wilkes’ 1841 map of the region. (Although the map is labeled “Oregon Territory,” that title would not be an official title for the region until its incorporation as a U.S. territory in 1848 under modified borders.)
As was inevitable in the age of Manifest Destiny, the further westward expansion of Americans settling and trading in the area would force a resolution to the vague separation of powers in the far-northwest region. After negotiations between newly-elected U.S