Fanning's Illustrated Gazetteer of the United States.... (New York: Phelps, Fanning & Co., 1853), 83.
CLAY COUNTY, situated in the westerly part of Missouri, on the north side of Missouri river. Area, 432 square miles. Seat of justice, Liberty. Pop. in 1830, 5,338; in 1840, 8,282; in 1850, 10,332.