Jerseyville is a part of the Metro-East region and the St. Louis Metropolitan Statistical Area.
As of the census of 2000, there were 7,984 people, 3,260 households, and 2,089 families residing in the city. The population density was 1,817.9 people per square mile (702.2/km²). There were 3,423 housing units at an average density of 779.4/sq mi (301.1/km²). The racial makeup of the city was 98.85% White, 0.09% African American, 0.18% Native American, 0.16% Asian, 0.10% from other races, and 0.63% from two or more races. Hispanic or Latino of any race were 0.54% of the population.
There were 3,260 households, out of which 31.5% had children under the age of 18 living with them, 49.1% were married couples living together, 12.1% had a female householder with no husband present, and 35.9% were non-families. 32.1% of all households were made up of individuals, and 17.7% had someone living alone who was 65 years of age or older. The average household size was 2.35, and the average family size was 2.97.
In the city, the population was spread out with 24.4% under the age of 18, 8.1% from 18 to 24, 27.2% from 25 to 44, 19.9% from 45 to 64, and 20.4% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 84.6 males. For every 100 females age 18 and over, there were 80.5 males.
The median income for a household in the city was $35,556, and the median income for a family was $46,832. Males had a median income of $37,312 versus $21,282 for females. The per capita income for the city was $20,178. About 5.8% of families and 7.3% of the population were below the poverty line, including 8.5% of those under age 18 and 4.7% of those age 65 or over.
Two major highways run through the city. US Highway 67 runs along a north-south route, while Illinois Route 16 runs along a west-east route. Also, Illinois Route 109 has its northern terminus in Jerseyville at US Highway 67.
A four-lane expansion of US Highway 67 in Jerseyville has been in the planning stages for years, and is currently in Illinois' five-year road construction plan. The plan includes the Jerseyville Bypass, which is expected to go around the eastern portion of the city when it is completed. Construction of the bypass has not started yet, but all of the work prior to actual road construction is scheduled to be completed by 2012. This is a part of the completion of the entire US Highway 67 four-lane project in Illinois between Godfrey and the Quad Cities area.