Rock Island is a city in and the county seat of Rock Island County, Illinois, United States. The original Rock Island, from which the city name is derived, is the largest island on the Mississippi River. It is now called Arsenal Island. The population was 39,018 at the 2010 census. Located on the Mississippi River, it is one of the Quad Cities, along with neighboring Moline, East Moline, and the Iowa cities of Davenport and Bettendorf. The Quad Cities has a population of about 380,000. The city is home to Rock Island Arsenal, the largest government-owned weapons manufacturing arsenal in the US, which employs 6,000 people.
Rock Island is located at 41°29′21″N 90°34′23″W / 41.48917°N 90.57306°W / 41.48917; -90.57306 (41.489083, -90.573154).
According to the 2010 census, Rock Island has a total area of 17.872 square miles (46.29 km), of which 16.85 square miles (43.64 km) (or 94.28%) is land and 1.022 square miles (2.65 km) (or 5.72%) is water.
As of the census of 2000, there were 39,684 people, 16,148 households, and 9,543 families residing in the city. The population density was 2,492.0 people per square mile (962.4/km²). There were 17,542 housing units at an average density of 1,101.6 per square mile (425.4/km²). The racial makeup of the city was 77.13% White, 17.17% African American, 0.28% Native American, 0.75% Asian, 0.07% Pacific Islander, 2.41% from other races, and 2.19% from two or more races. Hispanic or Latino of any race were 5.90% of the population.
There were 16,148 households out of which 26.4% had children under the age of 18 living with them, 41.2% were married couples living together, 14.2% had a female householder with no husband present, and 40.9% were non-families. 34.5% of all households were made up of individuals and 14.3% had someone living alone who was 65 years of age or older. The average household size was 2.31 and the average family size was 2.97.
In the city the population was spread out with 23.0% under the age of 18, 13.1% from 18 to 24, 25.7% from 25 to 44, 21.9% from 45 to 64, and 16.3% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 89.5 males. For every 100 females age 18 and over, there were 86.1 males.
The median income for a household in the city was $34,729, and the median income for a family was $45,127. Males had a median income of $32,815 versus $23,378 for females. The per capita income for the city was $19,202. About 10.9% of families and 14.5% of the population were below the poverty line, including 22.5% of those under age 18 and 8.4% of those age 65 or over.
Rock Island Illinois neighborhoods include: 23rd Ave, 35th and 35th, 38th and 38th, Arsenal Gateway, Audubon, Broadway District, East Central / 45th ST, Eugene Field, French Farms, Greenbush, Highland Park, Hill Top, Keystone, Longview, Rock Island/Milan Border, Salem Court, Saukie, W Rock Island