In 1816, the year Indiana gained statehood, the U.S. Congress donated four sections of federal land to establish a permanent seat of state government.[32] Two years later, under the Treaty of St. Mary's (1818), the Delaware relinquished title to their tribal lands in central Indiana, agreeing to leave the area by 1821.[16] This tract of land, which was called the New Purchase, included the site selected for the new state capital in 1820.[33] The indigenous people of the land prior to systematic removal are the Miami Nation of Indiana (Miami Nation of Oklahoma) and Indianapolis makes up part of Cession 99; the primary treaty between the indigenous population and the United States was the Treaty of St. Mary's (1818).[34]