Rock Island Arsenal is a census-designated place (CDP) in Rock Island County, Illinois, United States. The population was 149 at the 2010 census. The island contains the Rock Island National Cemetery.GeographyRock Island Arsenal is located at .According to the United States Census Bureau, the CDP has a total area of 2.6sqmi, of which 1.6sqmi is land and 1.0sqmi is water.DemographicsAs of the census of 2000, there were 145 people, 43 households, and 40 families residing in the CDP. The population density was 90.9 people per square mile (35.2/km²). There were 43 housing units at an average density of 27.0/sq mi (10.4/km²). The racial makeup of the CDP was 62.76% White, 28.28% African American, 1.38% Native American, 3.45% from other races, and 4.14% from two or more races. Hispanic or Latino of any race were 2.76% of the population.There were 43 households out of which 79.1% had children under the age of 18 living with them, 88.4% were married couples living together, 4.7% had a female householder with no husband present, and 4.7% were non-families. 4.7% of all households were made up of individuals and none had someone living alone who was 65 years of age or older. The average household size was 3.37 and the average family size was 3.46.
