Fanning's Illustrated Gazetteer of the United States... (New York: Phelps, Fanning & Co., 1853), 235.
MORAGN COUNTY, situated in the westerly part of Illinois, with Illinois river on the west. Area, 510 square miles. Seat of justice, Jacksonville. Pop. in 1830, 12,714; in 1840, 19,547; in 1850, 16,064.