Oregon
The Monroe Doctrine of 1823 warned European nations against the expansion of territories in the New World, essentially closing it to European colonization. The Europeans didn’t go away. There were the Spanish in Mexico, South America, and the Caribbean, where the British and Dutch also had interests, the Russians in California, and the British in Canada. The Canadian boundary with the United States had been set as far as the Rocky Mountains, to the west, in the Oregon Territory, it was not. The old fur trail known as the Oregon Trail allowed Americans to migrate to the country, rich in lumber and furs. It was disputes between American and British fur traders which led to the Oregon dispute.
As President, John Tyler proposed a division of the Oregon Territory along the 49th parallel, with the British keeping the portion north of the parallel. The British, who did not want to lose access to the Columbia River, rejected Tyler’s offer and instead proposed that the Columbia serve as the border between the American Oregon Territory and British Canada. This was viewed by expansionists as arrogant and an attempt to acquire American territory through threats (the British proposal meant that what became the State of Washington would be Canadian territory). The expansionists demanded the entire Oregon Territory up to its then border with Alaska.
The debate was carried over into the Presidential election of 1844, and as in most presidential elections the issue was exaggerated between the opponents. There were demands for taking the entire territory from Great Britain by force if necessary and the slogan 54 40 or Fight was heard (referring to the latitude of the border with Alaska), though it was not a campaign slogan as is commonly believed. Although the Americans and British had a joint occupancy agreement in place, there were far more American settlers than British, who used the territory as a fur, lumber, and trading region.
James K. Polk adopted the side of the expansionists during the Presidential campaign, though not advocating the use of force, and won election by a narrow margin on a platform which included the United States annexing the entirety of Oregon. After entering office Polk announced he was terminating the joint occupation agreement, and offered the same proposal which his predecessor had, with the territory divided more or less equally. The British decided to accept the offer, and the 1846 Oregon Treaty formalized the agreement. The Senate easily ratified the treaty, in part because the looming war with Mexico made another war with Great Britain unwise.
It was during the Oregon dispute that the term manifest destiny was coined by John L. Sullivan. It was meant to signify the duty imposed by Divine Providence on the United States to spread its virtues and blessings across the continent, actions which clearly would not be taken by the British Empire, since they lacked American virtues. Manifest Destiny was presented as an argument for war, as it ensured that a war would be in the cause of good, rather than conquest as it would be by Great Britain. Wrote O’Sullivan of America’s right to claim all of Oregon, “And that claim is by the right of our manifest destiny to overspread and possess the whole of the continent which Providence has given us…”