United States Acquires Oregon Territory

The peaceful settlement between the United States and Great Britain that gave the United States Oregon was a major American diplomatic triumph that helped open the Pacific Northwest to American settlement.

Summary of Event

The Exploration;North America struggle for possession of the lush Oregon Country was among the most difficult and danger-fraught episodes in American westward expansion. At various times, Spain, Russia, Great Britain, and the United States laid claims to Oregon. Their claims rested on such diverse supports as papal bulls and imperial ukases, but most strongly upon voyages of discovery and exploration between the 1540’s and the 1790’s. Spanish navigators first mapped the California coast during the mid-sixteenth century and first sighted the mouth of the Columbia River Columbia River;discovery of in 1775. Oregon Territory;U.S. acquisition of
British Empire;and United States[United States]
[kw]United States Acquires Oregon Territory (June 15, 1846)
[kw]Acquires Oregon Territory, United States (June 15, 1846)
[kw]Oregon Territory, United States Acquires (June 15, 1846)
Oregon Territory;U.S. acquisition of
British Empire;and United States[United States]
[g]Canada;June 15, 1846: United States Acquires Oregon Territory[2420]
[g]United States;June 15, 1846: United States Acquires Oregon Territory[2420]
[g]British Empire;June 15, 1846: United States Acquires Oregon Territory[2420]
[c]Expansion and land acquisition;June 15, 1846: United States Acquires Oregon Territory[2420]
[c]Exploration and discovery;June 15, 1846: United States Acquires Oregon Territory[2420]
Cook, James
Aberdeen, fourth earl of
Mackenzie, Alexander
Thompson, David
Pakenham, Richard
Peel, Sir Robert
[p]Peel, Sir Robert[Peel, Robert];and Oregon Territory[Oregon Territory]
Polk, James K.
[p]Polk, James K.;and Oregon Territory[Oregon Territory]
Vancouver, George
Webster, Daniel
[p]Webster, Daniel;and Oregon Territory[Oregon Territory]

Russian Oregon;Russian claims on claims to the region arose from the voyage to Alaska in 1741 of Vitus Jonassen Bering Bering, Vitus Jonassen , a Danish mariner in the service of Czar Peter the Great. Russian interests followed the fur trade Fur trade;and Russia[Russia] south, and in 1821 the czar issued an edict (ukase) extending Russian’s sphere of influence as far south as the fifty-first parallel. British claims dated from Sir Francis Drake’s Drake, Sir Francis explorations along the northern California California;exploration of coast in 1579 during his voyage around the world. Almost two hundred years passed before another Englishman, Captain James Cook Cook, James , sailed along the coast between the forty-fourth parallel and northern Alaska Alaska;exploration of in 1778 and claimed the region for the British crown. However, the British government ordered Cook not to interfere with previous Spanish claims to the northwest coast, adding that the government would recognize claims in the name of George III George III with consent of the indigenous population and in convenient situations. Fourteen years later, a British expedition led by George Vancouver Vancouver, George entered the great harbor now called Puget Sound and explored the lower reaches of the Columbia River Columbia River .

These maritime discoveries gave rise to overland expeditions from central Canada. Alexander Mackenzie Mackenzie, Alexander , the leader of the British North West Company, a fur-trading enterprise based in Montreal Montreal;commerce , reached the Pacific coast in 1793 and thus became the first Euro-American to complete a successful overland journey across North America north of Mexico. Others, such as Simon Fraser and David Thompson Thompson, David , of the British Hudson’s Bay Hudson’s Bay Company[Hudsons Bay Company];trading posts Company, followed. In the years between 1807 and 1810, Thompson set up a chain of trading posts on the western slope of the Rocky Mountains. These traders quickly expanded their operations into the area north of the Columbia River. Exploration;North America

American claims also were founded upon exploration. In 1788-1789, two Boston schooners, the Columbia and the Lady Washington, traded along the Oregon coast. Captain Robert Gray returned with the Columbia in 1791-1792 and sailed into the great river that he named after his vessel some two months before British explorers sighted the river. There is no evidence that either Gray or Vancouver Vancouver, George did anything to indicate that they took formal possession of the region in the name of the United States. However, the U.S. claim was bolstered by the Lewis and Clark expedition of 1804-1806. After their epochal trek up the Missouri River and across the Continental Divide Lewis and Clark expedition
Continental Divide , Lewis and Clark reached the mouth of the Columbia River. There they spent the winter of 1805-1806 and formally raised the U.S. flag over the entire territory. They did not explore north of the Columbia River. Although the first American settlement, the trading post established at Astoria Astoria, Oregon in 1811, ultimately failed, it indicated future American interest in Oregon.

Of the four powers that had made claims to the Oregon Country based on acts of discovery and exploration, only Great Britain and the United States remained in competition for the region by 1825. In the Adams-Onís Treaty Adams-Onís Treaty (1819)[Adams Onis Treaty] of 1819, Spain relinquished its claims north of the forty-second parallel to the United States, In 1824, Russia and the United States signed a treaty by which Russia accepted 54° 40 north latitude as the southern limit of its territory. A similar arrangement was made the next year between Russia and Great Britain.

By the mid-1820’s not only had the struggle for Oregon been limited to the United States and Great Britain, but the area in contention had been defined as the region west of the Rockies between 42° and 54° 40 north latitude. Over the next twenty years, efforts were made to reach an acceptable division of this territory. Although both sides were to raise and maintain claims unwarranted by the facts of exploration or settlement, the struggle focused on the Columbia River Columbia River and the triangular-shaped region between the Columbia and 49° north latitude, including the great harbor of Puget Sound.

President James K. Polk.

(Library of Congress)

Since Great Britain’s prime concern was to protect its commercial interests, the British insisted upon sovereignty over the Columbia River south of the forty-ninth parallel to the Pacific Ocean. The United States argued for extension of the 49° line—which already served as the boundary between the United States and Canada east of the Rockies—from the Rockies to the Pacific, and offered the privilege of free navigation of the Columbia River Columbia River to British subjects. During the 1820’s, neither side was willing to make significant concessions, and Oregon remained a contested land. In 1827 the two powers reconfirmed arrangements made in 1818 which provided for joint occupation of the territory and free entry of American and British subjects into Oregon without prejudice to the claims of either power.

Over the next fifteen years, Oregon was not the subject of diplomatic negotiation between the United States and Britain. However, much was taking place to force resolution of the rival claims. Although immigration of Americans into the region was not to become significant until after 1841—when great numbers of pioneers, possessed by “Oregon fever,” came plodding west over the Oregon Trail Oregon Trail —the stage was set during the 1830’s by the missionary activities of Jason Lee Lee, Jason , Marcus Whitman Whitman, Marcus , and others who spread tales of Oregon’s rich soil and mild climate. In 1845 alone, some three thousand immigrants reached this promised land, and by the end of that year about five thousand Americans were in the region south of the Columbia River, against some seven hundred British, mostly fur trappers and traders, north of the river. It was almost inevitable that the Americans would clamor for clear title to the land they occupied, and that the U.S. government would respond.

During the Webster-Ashburton Webster-Ashburton Treaty (1842)[Webster Ashburton Treaty (1842)] negotiations over the U.S.-Canadian boundary in 1842, U.S. secretary of state Daniel Webster Webster, Daniel
[p]Webster, Daniel;and Oregon Territory[Oregon Territory] expressed a willingness to concede American claims to most of the territory north of the Columbia River, while retaining the Olympic Peninsula and harbors in Puget Sound. In return, Great Britain was to exert pressure on Mexico Mexico;and California[California]
California;and Mexico[Mexico] to cede California north of the thirty-sixth parallel to the United States. However, American settlers in the West reacted violently to this proposed “surrender” of Oregon, reflecting the growing importance of that territory as a political issue and its central place in the mysticism of “manifest destiny.” Manifest destiny;and Oregon[Oregon]

Despite the campaign oratory and slogans of the Democrats in the presidential election of 1844 Presidency, U.S.;election of 1844 , most Americans were reluctant to fight for the Oregon territory north to 54° 40 . The winner of the election, President James K. Polk Polk, James K.
[p]Polk, James K.;and Oregon Territory[Oregon Territory] did not consider his election a mandate to occupy the whole of Oregon. Concerned about the implications of Britain’s reaction to American public bravado, the president privately approached Richard Pakenham, Pakenham, Richard the British minister to the United States, with an offer to divide Oregon at the forty-ninth parallel. Although hardly a great step toward compromise, 49° was much less threatening than 54° 40 , since previous administrations had proposed a similar settlement on three occasions. Pakenham committed the grievous error of rejecting the American proposal upon his own initiative. Polk, however, now could portray himself as the injured party and abruptly withdrew the 49° compromise. It was, he said, Great Britain’s turn to offer substantial concessions.

In his annual message to Congress in December, 1845, Polk Polk, James K.
[p]Polk, James K.;and Oregon Territory[Oregon Territory] stated that the United States was ready to support its claim to the whole of Oregon, basing his position upon the principle of opposition to the establishment of any European “colony or dominion” upon the North American continent. This statement, henceforth, was known as the Polk Corollary to the Monroe Doctrine Monroe Doctrine (1823);Polk Corollary . In brief, it stated that “the people of this continent alone have the right to decide their own destiny”; that no European power should interfere to prevent the union of the United States with another independent state of the North American continent “because it might disturb the balance of power”; and that “no future European colony or dominion shall with our consent be planted or established on any part of the North American continent.”

After four months of debate embittered by sectional and political conflict, Congress passed a resolution on April 22, 1846, that empowered Polk Polk, James K.
[p]Polk, James K.;and Oregon Territory[Oregon Territory] to terminate the Oregon joint occupation arrangement of 1827 with one year’s notice. Thus, after that one-year period elapsed, the two nations faced open conflict or embarrassing retreat. In Great Britain the Conservative government of Sir Robert Peel Peel, Sir Robert
[p]Peel, Sir Robert[Peel, Robert];and Oregon Territory[Oregon Territory] was immersed in the domestic struggle over repeal of the Corn Laws Corn Laws;repeal of and did not want a conflict with the United States. America’s preeminent place in British trade also helped to cool British irritation. Nevertheless, Oregon was a ticklish political issue in Britain, and Peel’s government was dissolved in December, 1846, after an aggressive Whig Whig Party (British);and Oregon[Oregon] campaign to denounce Tory cowardice regarding Oregon. The Whigs, however, found it impossible to form a new government and promised to observe a truce with the Tories while a settlement of the Oregon crisis was sought.

Lord Aberdeen Aberdeen, fourth earl of , the foreign secretary of Great Britain, drew up a treaty proposal that reflected almost total acceptance of American demands and suggested a boundary of 49° to the strait of Juan de Fuca if Great Britain could be guaranteed free navigation of the Columbia River Columbia River . Polk Polk, James K.
[p]Polk, James K.;and Oregon Territory[Oregon Territory] received this proposal officially on June 6, 1846, almost a month after issuing a declaration of war against Mexico. On June 10, he sent the treaty without change to the Senate. Five days later, on June 15, 1846, the Senate approved and ratified it.


The Oregon settlement was a great diplomatic success for the United States. By more than balancing the concessions offered to the British in the Webster-Ashburton Treaty, the United States gained rich and strategically situated land to which Great Britain possessed stronger claims. This favorable outcome was not primarily Polk’s Polk, James K.
[p]Polk, James K.;and Oregon Territory[Oregon Territory] achievement; to a great extent it was a victory of time and circumstance.

Further Reading

  • Galbraith, John S. The Hudson’s Bay Company as an Imperial Factor, 1821-1869. Berkeley: University of California Press, 1957. A model study of the relations between special economic interests and national foreign policy.
  • Gough, Barry M. Distant Dominion: Britain and the Northwest Coast of North America, 1579-1809. Vancouver: University of British Columbia Press, 1980. A comprehensive study of British motives for exploring the northwest coast.
  • Graebner, Norman A. Empire on the Pacific: A Study in American Continental Expansion. New York: Ronald Press, 1955. Author argues against “manifest destiny” sentiment for American expansion into the Pacific Northwest and Oregon.
  • Haynes, Sam W. James K. Polk and the Expansionist Impulse. Edited by Oscar Handlin. 2d ed. New York: Longman, 2002. Biography of Polk that looks especially closely at his support for expanding American territory and places it in a broad political and social context.
  • Merk, Frederick. The Oregon Question: Essays in Anglo-American Diplomacy and Politics. Cambridge, Mass.: Harvard University Press, 1967. Essays essential to critically examining the many foreign and American myths that influenced the Oregon Treaty of 1846.
  • Pethick, Derek. The Nootka Connection: Europe and the Northwest Coast, 1790-1795. Vancouver, B.C.: Douglas & McIntyre, 1980. A comparative study of expanding American, British, Russian, and Spanish exploration and trading interests in the northwest coast region, which included Oregon.
  • Seigenthaler, John. James K. Polk. New York: Times Books, 2003. Study of Polk’s one-term presidency that counts Polk’s acquisition of Oregon Territory among the achievements that made Polk a successful president.
  • Sellers, Charles G. Continentalists, 1843-1846. Vol. 2 in James K. Polk. Princeton, N.J.: Princeton University Press, 1966. Discusses Polk’s role in the settlement of the Oregon question.

Lewis and Clark Expedition

American Fur Company Is Chartered

Astorian Expeditions Explore the Pacific Northwest Coast

Treaty of Ghent Takes Effect

President Monroe Articulates the Monroe Doctrine

Frémont Explores the American West

Webster-Ashburton Treaty Settles Maine’s Canadian Border

Fraser River Gold Rush Begins

Treaty of Washington Settles U.S. Claims vs. Britain

Related Articles in <i>Great Lives from History: The Nineteenth Century, 1801-1900</i><br />

Sir Robert Peel; James K. Polk; David Thompson; Daniel Webster. Oregon Territory;U.S. acquisition of
British Empire;and United States[United States]