The following outline traces the territorial evolution of the U.S. state of Oregon.
Outline
Historical territorial claims of Spain in the present state of Oregon: Nueva California, 1768–1804 Gran Cuenca, 1776–1821 Alta California, 1804–1821 Adams-Onis Treaty of 1819 Historical international territory in the present state of Oregon: Oregon Country, 1818–1846 Anglo-American Convention of 1818 Provisional Government of Oregon (extralegal), 1843–1849 Oregon Treaty of 1846 Historical political divisions of the United States in the present state of Oregon: Unorganized territory created by the Oregon Treaty, 1846–1848 Territory of Oregon, 1848–1859 Oregon Organic Act, August 14, 1848 Northern portion of Oregon Territory incorporated in new Washington Territory, March 2, 1853 State of Deseret (extralegal), 1849–1850 State of Oregon since 1859 Oregon Statehood Act, February 14, 1859 (Eastern portion of territory transferred to Territory of Washington)