Fanning's Illustrated Gazetteer of the United States.... (New York: Phelps, Fanning & Co., 1853), 18.
ADAMS COUNTY, south part of Pennsylvania, about 20 miles in length, 18 in width, and contains 360 square miles. The surface is extremely diversified by hill and dale, and the soil fertile and well-watered. Courts are held at Gettysburgh, the chief town. Pop. in 1820, 19,681; in 1830, 21,379; in 1840, 23,044; in 1850, 25,981.