The following chronology traces the territorial evolution of the U.S. State of Idaho.
Timeline
Historical territorial claims of Spain in the present State of Idaho: Gran Cuenca, 1776–1821 Adams-Onis Treaty of 1819 Historical international territory in the present State of Idaho: 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 Idaho: Unorganized territory created by the Oregon Treaty, 1846–1848 Territory of Oregon, 1848–1859 State of Deseret (extralegal), 1849–1850 Territory of Washington, 1853–1889 Territory of Idaho, 1863-1890 State of Idaho since 1890