Oregon is the 33rd State Admitted to the Union

Act of Congress Admitting Oregon to the Union (dated February 14, 1859)

Whereas the people of Oregon have framed, ratified and adopted a constitution of state government which is republican in form, and in conformity with the Constitution of the United States and have applied for admission into the Union on an equal footing with the other states; therefore --

1. Admission of State--Boundaries
That Oregon be, and she is hereby, received into the Union on an equal footing with the other states in all respects whatever, with the following boundaries: In order that the boundaries of the state may be known and established, it is hereby ordained and declared that the State of Oregon shall be bounded as follows, to wit: Beginning one marine league at sea, due west from the point where the forty-second parallel of north latitude intersects the same, thence northerly, at the same distance from the line of the coast lying west and opposite the state, including all islands within the jurisdiction of the United States, to a point due west and opposite the middle of the north ship channel of the Columbia River; thence easterly, to and up the middle channel of said river, and, where it is divided by islands, up the middle and widest channel thereof, to a point near Fort Walla Walla, where the forty-sixth parallel of north latitude crosses said river, thence east, on said parallel, to the middle of the main channel of the Shoshone or Snake River; thence up the middle of the main channel of said river, to the mouth of the Owyhee River; thence due south, to the parallel of latitude forty-two degrees north; thence west, along said parallel, to the place of beginning, including jurisdiction in civil and criminal cases upon the Columbia River and Snake River, concurrently with states and territories of which those rivers form a boundary in common with this state.

2. Concurrent Jurisdiction on Columbia & Other Rivers--Navigable Waters to be Common Highways
The said State ...

Starting in 1842–1843, the Oregon Trail brought many new American settlers to Oregon Country. For some time, it seemed that Britain and the United States would go to war for a third time in 75 years (see Oregon boundary dispute), but the border was defined peacefully in 1846 by the Oregon Treaty. The border between the United States and British North America was set at the 49th parallel. The Oregon Territory was officially organized in 1848.

Settlement increased because of the Donation Land Claim Act of 1850, in conjunction with the forced relocation of the native population to Indian reservations in Oregon.

The state was admitted to the Union on February 14, 1859. Founded as a refuge from the disputes over slavery that were tearing apart other places in the United States, such as Kansas, Oregon had a "whites only" clause in its state Constitution at the time of its admission; the only state thus admitted.

At the outbreak of the American Civil War, regular U.S. troops were withdrawn and sent east. Volunteer cavalry were recruited in California and sent north to Oregon to keep peace and protect the populace. The First Oregon Cavalry served until June 1865.