Formed March 4, 1837 (72nd county)
DeKalb County (100,415), Sycamore (18,576), DeKalb (40,301)
A governmental look is given the 1903 masonry facility located on a square at State, Maple, Exchange, and Main streets. Illinois State Highway 23 is State Street in the town. Herbert T. Hazelton provided these Classical Revival designs for the courthouse. The building was enlarged in 2012. An Administration Center was built in 1982 and a Legislative Center in 2002. The grounds feature veteran memorials.
DeKalb County government consists of a sheriff, an attorney, a coroner, a clerk, a treasurer, and an assessor (executive). It has 24 Board Members (legislative.) Twelve Circuit Court Judges serve DeKalb and Kendall counties and a court clerk serves DeKalb County (judicial.) The county is in northern Illinois to the west of Chicago, Illinois and southeast of Rockford, Illinois. The county center is 11.7 miles South of Sycamore nearer Cortland. The county is surrounded clockwise by Boone, McHenry, Kane, Kendall, La Salle, Lee, Ogle, and Winnebago counties. The county was organized on March 4, 1837 as 72nd county. Coltonville had the earlier courthouse until 1840 when Sycamore became the county seat. The county was taken from Kane County. The county is named for Revolutionary War hero Johann de Kalb. The county seat is named for a local river.
The area of the county is 631 square miles. It is 30 out of 102 in the state. It ranks 20 out of 102 in population in the state. It has a density of 159.1 persons per square mile making it 19 out of 102 in the state. DeKalb County has 85.9% of its population in its incorporated areas. United States Highway 30 crosses east to west in the county from Kane County to Lee County. United States Highway 34 cuts the extreme southeast corner coming from Kendall County, east, and going into La Salle County, south. The county is a rectangle with a small nose extending out of the northeast corner. Sycamore is located in the northeast quarter of the county. DeKalb is north of center in the county. Sycamore is the county seat and De Kalb is the largest city. Sycamore is 18.5% of the county population while De Kalb is 40.1% of the county population. The county and largest city are pronounced DI-KAELB. The county seat is pronounced SIK-A-MORE. This county is in the Chicago-Naperville-Joliet Metropolitan Statistical Area.
Cortland
DeKalb
Genoa
Hinckley
Kingston
Kirkland
Malta
Shabbona
Sycamore
Waterman
Lee
Sandwich
Somonauk