Fanning's Illustrated Gazetteer of the United States.... (New York: Phelps, Fanning & Co., 1853), 362.
UNION COUNTY, situated in the central part of Pennsylvania, with Suequehanna river on the east. Area, 520 square miles. Face of the country, mountainous and broken; soil, in the valleys productive. Seat of justice, New Berlin. Pop. in 1820, 18,619; in 1830, 20,656; in 1840, 22,787; in 1850, 26,083.