GRUNDY COUNTY, situated toward the northeastern part of Illinois, and traversed by Des Plaines river. Area, 324 square miles. Seat of justice, Morris. Pop. in 1850, 3,023.

WARREN COUNTY, situated in the west part of Illinois.  Area, 600 square miles.  Seat of justice, Monmouth.  Pop. in 1830, 308; in 1840, 6,739; in 1850, 8,176.

GREENE COUNTY, situated toward the westerly part of Illinois, with Illinois river on the west. Area, 942 square miles. Face of the country rolling; soil, fertile. Seat of justice, Carrollton. Pop. in 1830, 7,674; in 1840, 11,951; in 1850, 3,658.

GALLATIN COUNTY, situated on the easterly boundary of Illinois, with Ohio and Wabash rivers on the east. Area, 760 square miles. Face of the country, undulating; soil, productive. Seat of justice, Equality. Pop. in 1820, 3,155; in 1830, 7,405; in 1840, [illegible]; in 1850, 5,137.

FULTON COUNTY, situated toward the westerly part of Illinois, with Illinois river on the sotheast. Area, 874 square miles. Seat of justice, Lewiston. Pop. in 1830, 1,841; in 1840, 13,142; in 1850, 22,508.

WABASH COUNTY, situated on the southeasterly boundary of Illinois, with Wabash river on the southwest.  Area, 180 square miles.  Seat of justice, Mount Carmel. Pop. in 1840, 4,210; in 1850, 4,690.

TAZEWELL COUNTY, situated in the central part of Illinois, with Illinois river on the northwest.  Area, 1,130 square miles, Illinois river on the northwest.  Area, 1,130 squared miles.  Seat of justice, Tremont.  Pop. in 1830, 4,716; in 1840, 7,221; in 1850, 12,052.

STARK COUNTY,  situated toward the northwest part of Illinois, and traversed by Spoon river.  Area, 288 square miles.  Seat of justice, Toulon.  Pop. in 1840, 1,573; in 1850, 3,710.

SAINT CLAIR COUNTY, situated on the southwesterly boundary of Illinois, with Mississippi river on the west, and traversed by the Kaskaskia.  Area, 649 square miles.  Face of the country, even; soil, generally fertile.  Seat of justice, Bellville.  Pop. in 1820, 5,253; in 1830, 7,078; in 1840, 13,631; in 1850, 20,181.

SHELBY COUNTY, situated in the central part of Illinois, and traversed by Kaskaskia river.  Area, 1,080 square miles.  Soil, in many parts, fertile.  Seat of justice, Shelbyville.  Pop. in 1830, 2,972; in 1840, 6,639; in 1850, 7,807.