Indian Territory , originally "the entire part of the United States west of the Mississippi and not within states Missouri and Louisiana or Arkansas Territory". Never an organized area, it was soon confined to the current state of Oklahoma , excluding the Panhandle and Greer County. The Choctaw , Creek , Seminole , Cherokee and Chickasaw Tribes were forcibly brought into this area between 1830 and 1843, and a law of June 30, 1834 designated the country as Indian Country (later known as Indian Territory) aside .
Britannica Quiz United States of America:Fact or Fiction? You may be familiar with New York and Nebraska, but there are 11 US states with names beginning with the letter "N " start? See if your knowledge of names is quick or deaf with this state and city quiz. In 1866, the western half of Indian territory was ceded to the United States, which opened part of it to white settlers in 1889. This portion became the Territory of Oklahoma and in 1890 included finally all ceded territories in 1866. The two territories were united and incorporated into the Union as the state of Oklahoma in 1907.