Rock Island County is a county located in the U.S. state of Illinois. As of 2000, the population was 149,374. Its county seat is Rock Island, Illinois. It is one of the four counties that make up the Davenport-Moline-Rock Island Metropolitan Statistical Area.
According to the U.S. Census Bureau
, the county has a total area of 451 square miles
), of which, 427 square miles (1,105 km²) of it is land and 24 square miles (63 km²) of it (5.41%) is water.
Andalusia, Blackhawk, Bowling, Buffalo Prairie, Canoe Creek, Coal Valley, Coe, Cordova, Drury, Edgington, Hampton, Moline, Port Byron, Rock Island, Rural, South Moline, South Rock Island, Zuma
Rock Island County was formed in 1831 out of Jo Daviess County
. It was named for Rock Island, an island in the Mississippi River
now known as Arsenal Island.
As of the census
of 2000, there were 149,374 people, 60,712 households, and 39,159 families residing in the county. The population density
was 350 people per square mile (135/km²). There were 64,489 housing units at an average density of 151 per square mile (58/km²). The racial makeup of the county was 85.52% White
, 7.54% Black
or African American
, 0.27% Native American
, 1.02% Asian American
, 0.03% Pacific Islander
, 3.76% from other races
, and 1.86% from two or more races. 8.56% of the population were Hispanic
of any race. 23.1% were of German
, 10.3% Irish
, 8.4% American
, 7.2% English
, 6.6% Swedish
and 5.5% Belgian
ancestry according to Census 2000
There were 60,712 households out of which 28.90% had children under the age of 18 living with them, 49.10% were married couples living together, 11.60% had a female householder with no husband present, and 35.50% were non-families. 30.20% of all households were made up of individuals and 12.50% had someone living alone who was 65 years of age or older. The average household size was 2.38 and the average family size was 2.97.
In the county the population was spread out with 23.80% under the age of 18, 10.00% from 18 to 24, 27.30% from 25 to 44, 23.80% from 45 to 64, and 15.10% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 94.40 males. For every 100 females age 18 and over, there were 91.40 males.
The median income for a household in the county was $38,608, and the median income for a family was $47,956. Males had a median income of $35,998 versus $24,234 for females. The per capita income for the county was $20,164. About 8.10% of families and 10.70% of the population were below the poverty line, including 15.70% of those under age 18 and 6.80% of those age 65 or over.
Cities and towns
Rock Island County is divided into these eighteen townships