Rock Island

Formed January 1, 1831 (56^th county)

Rock Island County (144,678), Rock Island (37,109), Moline (42,993)

A classier masonry and stone courthouse was built in 1896 and remodeled in 1960.  It is augmented by a Justice Center built in 1999 and a County Administrative Center purchased in 1965.  Gunn & Curtis are the courthouse architects in a Romanesque style.  The courthouse is located at 15^th Street between 2^nd and 3^rd avenues.  United States Highway 67 is 15^th Street in the city.  The building features a rotunda which is hidden from the outside.  The grounds have veteran memorials.  Rock Island County was formed on January 1, 1831 out of Jo Daviess County as the 56^th county. Farnhamsburg was the first county seat followed by Rock Island in 1835.  The county and county seat are named for an island in the Mississippi River. 

Rock Island County government consists of a sheriff, an attorney, a coroner, a clerk, a treasurer, and an assessor (executive).  It has 19 Board Members (legislative.)  Twenty Circuit Court Judges serve Rock Island, Henry, Mercer, and Whiteside counties and a court clerk serves Rock Island County (judicial.) The county is in northwest Illinois on the border with Iowa.  Rock Island, Illinois, Moline, Illinois, Davenport, Iowa and Bettendorf, Iowa form the Quad-Cities.  The Mississippi River forms its northern and western borders.  The county center is in Rock Island .7 miles East of the city center.  The county is surrounded clockwise by Iowa and Whiteside, Henry, and Mercer counties. 

The area of the county is 427 square miles.  It is 67 out of 102 in the state.  It ranks 14 out of 102 in population in the state.  It has a density of 338.8 persons per square mile making it 11 out of 102 in the state.  Rock Island County has 88.3% of its population in its incorporated areas.  Interstate Highway 74 enters from the east, Henry County, and exits to the north, Iowa.  Interstate Highway 80 also goes from Henry County to Iowa.  Interstate Highway 88 comes from the northeast, Whiteside County, and terminates.  United States Highway 6 parallels Interstate Highway 80 from Henry County to Iowa.  United States Highway 67 enters from Iowa to the north and exits into Mercer County to the south.  United States Highway 150 parallels Interstate Highway 74 from Henry County but terminates in Rock Island County.  The county is shaped like a fishhook lying on its back.  The City of Rock Island is slightly south of the geographical county center.  Moline is immediately east of Rock Island.  Rock Island is the county seat and Moline is the largest city.  Rock Island is 25.7% of the county population while Moline is 29.7% of the county population.  The largest city is pronounced MOE-LEEN.  This county is in the Davenport-Moline-Rock Island Metropolitan Statistical Area.