In the Indian Removal Act of 1830 , Sullivan ’s lines were used for the removal of almost all Native Americans from the eastern portion of the United States ( in such events as the Trail of Tears ) . In 1832 , at the conclusion of the Black Hawk War , the Sac and Fox conceded the eastern section of Iowa and the western section of Illinois . In the terms the 12 mile stretch between the end of the Sullivan Line and the Mississippi was conceded ( in what was called Half Breed Tract because it was to be set aside for mixed race residents ) . In 1836 , the western boundary of the Sullivan Line latitude was extended 45 miles west to the Missouri River just south of Hamburg , Iowa when the federal government relocated the already relocated tribes further west in the Platte Purchase . The land was annexed to Missouri
Trail of Tears
Trail of Tears
Sullivan Line