The Curtis Act of 1898 was an amendment to the United States Dawes Act; it resulted in the break-up of tribal governments and communal lands in Indian Territory (now Oklahoma) of the Five Civilized Tribes of Indian Territory: the Choctaw, Chickasaw, Muscogee (Creek), Cherokee, and Seminole. These tribes had been previously exempt from the 1887 General Allotment Act (Dawes Act) because of the terms of their treaties. In total, the tribes immediately lost control of about 90 million acres of their communal lands; they lost more in subsequent years.