Oregon Treaty of 1846 Largely Settles U. S.-Canadian Border [otd 06/15]

President Polk. Library of Congress.

On June 15, 1846, the United States and Great Britain reached an agreement that settled almost all the remaining disputes about the border between the U. S. and Canada. This treaty, arranged under President James K. Polk, meant that the future states of Idaho, Oregon, Washington, and some of Montana were indeed part of the United States.

The U. S.-Canadian boundary had been established as far west as the Continental Divide by the "joint occupancy" treaty of 1818 [blog, October 20]. That had left the area west of the Divide between latitude 42º N and 54º 40' N "in limbo." People commonly referred to that region as the “Oregon Country,” and some in the U. S. wanted all of it. (Note that "we" usually say "Americans" in cases like this ... but citizens of Canada are also "Americans," so I've tried to be very specific.)

Russian claims to the area complicated matters until they reached accommodations with the other two countries in 1824-1825. The Russians finally abandoned Fort Ross in northern California (Spanish-claimed territory) in 1841.

In the U. S., the issue boiled over during the 1844 presidential elections. The Democratic Party platform took an aggressive expansionist stance. Platform provisions demanded the annexation of Texas and laid claim to the entire Oregon Country. Their candidate, James K. Polk, eagerly ran on that platform. The Whigs equivocated and their candidate, Henry Clay, could not seem to make up his mind.

Southern expansionists supported the Texas annexation, partly because that would add another slave state to the Union. Northerners wanted the Oregon Country because it was seen as our “due” and would add several non-slave states. Claims and counter-claims muddled the Oregon issue in the minds of voters, whereas the Texas situation was clear-cut.

Disputed Pacific Northwest region. Slightly modified Oregon Country map from Wikipedia Commons, original creator not specifically identified.

Polk won the election by a close margin in the popular vote: less than 40 thousand out of over 2.6 million cast. Outgoing President John Tyler, a Whig, moved quickly to "steal his thunder." With Tyler’s urging, Congress passed a joint resolution to annex Texas. Texans then voted for a matching Ordinance of Annexation. Thus, statehood for Texas became a non-issue for the new administration.

With Texas relegated to "old news," rhetoric on the Oregon Question heated up. The inflammatory slogan, "Fifty-four Forty or Fight," espoused the position that the U. S. should demand the maximum concession on the Canadian border dispute.

However, as Texas statehood moved toward reality, it became clear that war with Mexico would almost certainly result. At the time, chaos gripped Mexican leadership, with the ministerial “lineup” changing almost monthly. The only constant, it seemed, was popular anger over the loss of Texas. Officials who made concessions to the U. S. would be driven from office. So, barring some major change in Polk’s position, Mexican leaders almost had to go to war … even though many knew Mexico would probably lose.

At the same time, American representatives in London warned that annoyed British officials were now considering preparations for war. Polk and his colleagues realized they were in no position to fight two foreign wars, especially when one of the opponents was the greatest power on Earth.

Thus, “cooler heads prevailed” and the new treaty ended the dispute with Great Britain just over a month after Congress declared war on Mexico.
                                                                                 

References: [Brit]

Walter T. K. Nugent, Habits of Empire: A History of American Expansion, Alfred A. Knopf, New York (2008).

Samuel Eliot Morison, The Oxford History of the American People, Oxford University Press (1965).