JASPER COUNTY, situated in the southeasterly part of Illinois. Area, 475 square miles. Soil poor. Seat of justice, Newton. Pop. in 1840, 1,472; in 1850, 3,220.

JACKSON COUNTY, situated on the southwest boundary of Illinois, on Mississippi river. Area, 576 square miles. Face of the country, even. Seat of justice, Brownsville. Pop. in 1820, 1,542; in 1830, 1,872; in 1840, 3,566; in 1850, 5,862.

WAYNE COUNTY, situated in the southeast part of Illinois, with Little Wabash river on the east.  Area, 720 square miles.  Seat of justice, Fairfield.  Pop. in 1820, 111; in 1830, 2,553; in 1840, 5,133; in 1850, 6,828.

IROQUOIS COUNTY, situated on the east boundary of Illinois, and traversed by the Iroquois river. Area, 1,428 square miles. Seat of justice, Middleport. Pop. in 1840, 1,695; in 1850, 4,149.

HENRY COUNTY, situated in the northwesterly part of Illinois, with Rock river on the northwest. Area, 840 square miles. Seat of justice, Cambridge. Pop. in 1840, 1,260; in 1850, 3,807.

HENDERSON COUNTY, situated on the western boundary of Illinois, with Mississippi river on the west. Area, ----- square miles. Seat of Justice, Oquawka. Pop. in 1850, 4,612.

WASHINGTON COUNTY, situated toward the south part of Illinois, with Kaskaskia river on the northwest.  Area, 656 square miles.  Seat of justice, Nashville.  Pop. in 1820, 1,517; in 1830, 1,674; in 1840, 4,810; in 1850, 6,593.

HARDIN COUNTY, situated in the southeastern part of Illinois, bounded on the east and south by Ohio river. Area, 100 square miles. Seat of justice, Elizabethtown. Pop. in 1840, 1,378; in 1850, 2,887.

HANCOCK COUNTY, situated on the western boundary of Illinois, with Mississippi river on the west. Area, 775 square miles. Face of the country even, consisting of prairie land; soil productive. Seat of justice, Carthage. Pop. in 1830, 483; in 1840, 9,946; in 1850, 14,652.

HAMILTON COUNTY, situated in the south easterly part of Illinois. Area, 432 square miles. Seat of justice, McLeansborough. Pop. in 1830, 2,616; in 1840, 3,945; in 1850, 6,362.