Fanning's Illustrated Gazetteer of the United States.... (New York: Phelps, Fanning & Co., 1853), 376.
WASHINGTON COUNTY, situated on the southeast boundary of Ohio, with Ohio river on the southeast, and traversed by Muskingum river. Area, 713 square miles. Face of the country, hilly; soil, near the rivers, good; elsewhere, unproductive. Seat of justice, Marietta. Pop. in 1820, 10,425; in 1830, 11,731; in 1840, 20,823; in 1850, 29,540.