Editing Oregon Territory (section)

==Background==
{{Main|Oregon Country}}

Originally inhabited by Native Americans, the region that became the Oregon Territory was explored by Europeans first by sea. The first documented voyage of exploration was made in 1777 by the Spanish, and both British and American vessels visited the region not long thereafter.<ref name=doh>{{cite book|title=Dictionary of Oregon History|date=1989|publisher=[[Binfords & Mort Publishing]]|pages=110|editor=Howard M. Corning}}</ref><ref name=Horner>Horner, John B. (1919). ''Oregon: Her History, Her Great Men, Her Literature''. The J.K. Gill Co.: Portland. pp. 28–29.</ref> Subsequent land-based exploration by [[Alexander Mackenzie (explorer)|Alexander Mackenzie]] and the [[Lewis and Clark Expedition]] and development of the fur trade in the region strengthened the competing claims of Great Britain and the United States.<ref name=fur>Horner, pp. 53–59.</ref>

The competing interests of the two foremost claimants were addressed in the [[Treaty of 1818]], which sanctioned a "joint occupation", by British and Americans, of a vast "[[Oregon Country]]" (as the American side called it) that comprised the present-day U.S. states of Oregon, Washington, and Idaho, parts of Montana and Wyoming, and the portion of what is now the Canadian province of [[British Columbia]] south of the parallel 54°40′ north.<ref name=joint>Corning, p. 129.</ref>