Fanning's Illustrated Gazetteer of the United States.... (New York: Phelps, Fanning & Co., 1853), 93.
COOS COUNTY, situated at the extreme north part of New Hampshire, on the easterly side of Connecticut river. Area, 1,600 square miles. Face of the country mountainous and generally broken; soil in many parts productive in grain and pasturage. Seat of justice, Lancaster. Pop. in 1820, 5,549; in 1830, 8,390; in 1840, 9,849; in 1850, 11,713.