In the 1850s the permanent of removal, the Osage Indians, from eastern Kansas, to the newly defined Indian Territory, today's Oklahoma, began. In 1871, the Osage abandoned their Reservation in Kansas and by 1872 had been settled on their new reservation in Indian Territory. The Osage had purchased their Reservation, from the Cherokee, with funds from the sale of their Kansas lands, by the U.S. to new white settlers. More than 3,600 full-blooded Osage Indians made the move.
By the 1890s the Osage had come under considerable pressure from Washington D.C. to divide their Reservations into individual allotments. In 1890s, oil had been discovered on the Osage Reservation. Then in 1906, the Osage were the last Indians in Oklahoma Territory to give up communal ownership of their Reservation. On June 28, 1906, Congress passed the Osage Allotment Act. Osage allotment was unlike that of any other tribe. Land was to be equally divided among the 2,229 tribal members. Because of the tribal ownership of mineral rights, the Osage Reservation would retain limited Reservation status.