Fanning's Illustrated Gazetteer of the United States.... (New York: Phelps, Fanning & Co., 1853), 348.
SUSSEX COUNTY, situated in the north part of New Jersey, with Delaware river on the northwest. Area, 415 square miles. Face of the country, diversified with hills, mountains, and marshy plains; soil, varied. Seat of justice, Newton. Pop. in 1810, 25,549; in 1820, 32,752; in 1830, 20,346; in 1840, 21,770; in 1850, 22,986.