Facts, information and articles about the Oregon Territory, a part of Westward Expansion from the Wild West Oregon Territory summary: The Territory of Oregon existed from August 1848 until February 1859. That period ended when Oregon became an American State on February 14, 1859. The Territory of Oregon encompassed the segments of present-day Idaho, Oregon, Washington, Wyoming and Montana as well as parts of British Columbia which is now a Canadian province. The Territory’s first capitol was Oregon City. The next capital was Salem and Corvallis became the capital city after Salem. When Oregon became a US state, the seat of government was transferred back to Salem again. The population of the Oregon Territory consisted mainly of Native Americans. The Europeans first explored the territory from the sea. The region became known for its fur-trade and the British Hudson’s Bay Company dominated the market. Since the fur-trade that developed in the region was extremely lucrative, many countries wanted to claim the land for themselves. The territorial claims often caused conflicts between the European colonists and the United States. In the late 1830s, trappers began to settle down on the land and more and more settlers and missionaries started to arrive to the territory. There was no organized government in those parts at the time. A group of settlers in the Willamette Valley discussed organizing a government in the region on their regular meetings and they created the Provisional Government of Oregon in 1841. In 1846 the Oregon Treaty was signed between the US and Britain to settle the boundary dispute. The British gained the land north of the 49th parallel, including the Vancouver Island and the United States received the territory south of the parallel.