The
Territory of Oregon was an
organized incorporated territory of the United States that existed from August 14, 1848, until February 14, 1859, when the southwestern portion of the territory was admitted to the
Union as the
State of Oregon. Originally claimed by several countries (See
Oregon Country), the region was divided between the U.S. and Great Britain in 1846. When established, the territory encompassed an area that included the current states of Oregon,
Washington, and
Idaho, as well as parts of
Wyoming and
Montana. The capital of the territory was first
Oregon City, then
Salem, followed briefly by
Corvallis, then back to Salem, which became the state capital upon Oregon's admission to the Union.