Indian Territory different from Indiana Territory
Description and geography
Indian Territory, also known as the Indian Territories and the Indian Country, was land in the United States reserved for the forced resettlement of Native Americans. As such, it was not a traditional territory for the tribes settled upon it. The general borders were set by the Indian Intercourse Act of 1834. The territory was located in the Central United States.
While Congress passed several Organic Acts that provided a path for statehood for much of the original Indian Country, Congress never passed an Organic Act for the Indian Territory. Indian Territory was never an organized incorporated territory of the United States. In general, tribes could not sell land to non-Indians (Johnson v. McIntosh). Treaties with the tribes restricted entry of non-Indians into tribal areas; Indian tribes were largely self-governing, were suzerain nations, with established tribal governments and well established cultures. The region never had a formal government until after the American Civil War.
After the Civil War, the Southern Treaty Commission re-wrote treaties with tribes that sided with the Confederacy, reducing the territory of the Five Civilized Tribes and providing land to resettle Plains Indians and tribes of the Midwestern United States.  These re-written treaties included provisions for a territorial legislature with proportional representation from various tribes.
In time, the Indian Territory was reduced to what is now Oklahoma. The Organic Act of 1890 reduced Indian Territory to the lands occupied by the Five Civilized Tribes and the Tribes of the Quapaw Indian Agency (at the borders of Kansas and Missouri). The remaining western portion of the former Indian Territory became the Oklahoma Territory.
The Oklahoma organic act applied the laws of Nebraska to the incorporated territory of Oklahoma Territory, and the laws of Arkansas to the still unincorporated Indian Territory, since for years the federal U.S. District Court on the eastern borderline in Ft. Smith, Arkansas had criminal and civil jurisdiction over the Territory.