Fanning's Illustrated Gazetteer of the United States.... (New York: Phelps, Fanning & Co., 1853), 347.
SULLIVAN COUNTY, situated on the west boundary of Indiana, with Wabash river on the west. Area, 430 square miles. Seat of justice, Sullivan. c. h. Pop. in 1830, 4,690; in 1840, 8,315; in 1850, 10,141.