KANE COUNTY, situated in the northeast part of Illinois, and traversed by Fox river. Area, 1,296 square miles. Seat of justice, Geneva. Pop. in 1840, 6,501; in 1850, 16,703.

JOHNSON COUNTY, situated in the south part of Illinois. Area, 486 square miles. Face of the country uneven; soil fertile. Seat of justice, Vienna. Pop. in 1820, 843; in 1830, 1,596; in 1840, 3,626; in 1850, 4,113.

BEAVER COUNTY, situated in the western boundary of Pennsylvania, and traversed by Ohio and Beaver rivers. Length, about 40 miles; mean breadth, 15; with an area of 600 square miles. The face of the country is broken and hilly; the soil generally fertile, well wooded and watered. Seat of justice, Beaver. Pop in 1820, 13,34O; in 1830, 24,183; in 1840, 29,368; in 1850, 26,689.

JO-DAVIESS COUNTY, situated at the northwest corner of Illinois, on the Mississippi river. Area, 724 square miles. Soil rich. Seat of justice, Galena. Pop. in 1830, 2,111; in 1840, 6,180; in 1850, 18,604.

JEFFERSON COUNTY, situated toward the south part of Illinois. Area, 576 square miles. Face of the country level. Seat of justice, Mount Vernon. Pop. in 1820, 691; in 1830, 2,555; in 1840, 5,762; in 1850, 8,109.

ARMSTRONG COUNTY, situated in the westerly part of Pennsylvania, and is watered by Alleghany river. Length, 35 miles; mean width, 20, with an area of about 700 square miles. The face of the country is hilly, rocky, and broken, though much of the soil consists of a fertile loam, particularly along the Alleghany river. Courts are held at Kittaning. Pop., in 1820, 10,324; in 1830, 17,695; in 1840, 28,365; in 1850, 29,560.

ALLEGHANY COUNTY, in the southwestern part of Pennsylvania. Watered by Alleghany, Youghiogheny, Monongahela, and Ohio rivers. Length of this county, 32 miles; mean breadth, 18, with an area of 575 square miles. The face of the country is peculiarly diversified by depressed vales, lying within large swelling hills, which are productive to their summits. In the bosom of these hills there exist inexhaustible beds of fine bituminous coal. Excellent lime and building stone also abounds. Courts are held at Pittsburgh. Pop.

WILL COUNTY, situated on the east boundary of Illinois, and traversed by Des Plaines river.  Area, 504 square miles.  Face of the country even; soil, generally fertile.  Seat of justice, Joliet.  Pop. in 1840, 10,167; in 1850, 16,703.

WHITESIDES COUNTY, situated on the northwest boundary of Illinois, with Mississippi river on the west, and traversed by Rock river.  Area, 770 square miles.  Seat of justice, Lyndon.  Pop. in 1840, 2,514; in 1850, 5,361.

WHITE COUNTY, situated on the southeasterly boundary of Illinois, with Wabash river on the east.  Area, 480 square miles.  Face of the country, even; soil, fertile.  Seat of justice, Carmi.  Pop. in 1820, 4,828; in 1830, 6,091; in 1840, 7,919; in 1850, 8,925.