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Bungled Borders in the Pacific Northwest (Part 1)

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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.)

Map of the Oregon Territory
Charles Wilkes. “Map of the Oregon Territory.” 1841. Library of Congress, Geography and Map Division.

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. President James K. Polk and British officials faltered on a compromise boundary at the 49th parallel, Polk, spurred on by his expansionist Democratic Party, would go further on his demands: claiming all land up to Parallel 54° 40′N for the United States.

Polk’s aggressive claim would include essentially all of the Oregon Country shown in Wilkes’ map, reaching all the way up to the southern edge of Russian-occupied Alaska. “Fifty-four forty or fight!” would become a rallying cry among Democrats supporting this expansion, but not all Americans supported the massive land grab. An 1846 cartoon by Edward Williams Clay, below, mocks the president’s handling of the issue. In the cartoon, a sleeping Polk is visited by the Devil, who disguises himself as former President and fellow expansionist Andrew Jackson and urges Polk to maintain his hardline stance on the 54° 40′N line.

Polk's Dream
Edward Williams Clay. “Polk’s Dream.” 1846. Library of Congress, Prints and Photographs Division.

Ultimately, cooler heads would prevail. With the Mexican-American War beginning just two months prior, British and American officials established the 49th parallel as the boundary with the signing of the Oregon Treaty on June 15, 1846. Both sides were satisfied to avoid another violent conflict. The Oregon Treaty is preserved in the National Archives and viewable online.

However, for all of the negotiations and hand-wringing to establish the border, the Oregon Treaty would still not lay the boundary issue completely to bed. The treaty established the international boundary for Oregon Country along the 49th parallel, but once the Strait of Georgia was reached, the boundary is instructed to follow the “middle of the channel” to the Strait of Juan de Fuca, which leads to the Pacific Ocean. Given the numerous small islands between Vancouver Island and the mainland of American territory, the exact path of the “middle of the channel” was not quite clear. Both the vagueness of the “middle of the channel” and the exacting nature of the 49th parallel set out in the Oregon Treaty would lead to two intriguing outcomes: tensions over control of the San Juan Islands and the strange case of Point Roberts.

Those parts of the story, as well as the pig that triggered an international incident, will appear in Part Two later this week.

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