DuPage County is a county located in the U.S. state of Illinois. Its county seat is Wheaton. According to the 2000 census, the population is 904,161. As of 2005, the estimated population is around 930,000. This county is part of Chicagoland. The county is divided into nine different townships: Downers Grove, Lisle, Naperville, York, Milton, Winfield, Addison, Bloomingdale & Wayne. DuPage is in the 630 area code.
The municipality that has the largest population enclosed within DuPage County is Naperville. Wheaton and Downers Grove are the next largest communities, respectively. A small portion of the City of Chicago is located within county limits but the area is primarily commercial and as of recent census estimates has only 230 residents.
According to the U.S. Census Bureau, the county has a total area of 337 miles. 334 miles is land and 3 miles (0.88%) is water.
The DuPage River and the Salt Creek flow through DuPage County.
DuPage County was formed in 1839 out of Cook County. It is named after the DuPage River, which flows through it.
As of the census² of 2000, there were 904,161 people, 325,601 households, and 234,432 families residing in the county. The population density was 1,046/km² (2,710/mi²). There were 335,621 housing units at an average density of 388/km² (1,006/mi²). The racial makeup of the county was 84.05% White, 3.05% Black or African American, 0.17% Native American, 7.88% Asian, 0.02% Pacific Islander, 3.12% from other races, and 1.71% from two or more races. 9.00% of the population is Hispanic or Latino of any race.
There were 325,601 households out of which 37.00% had children under the age of 18 living with them, 60.90% were married couples living together, 7.90% had a female householder with no husband present, and 28.00% were non-families. 22.90% of all households were made up of individuals and 6.80% had someone living alone who was 65 years of age or older. The average household size was 2.73 and the average family size was 3.27.
In the county the population was spread out with 26.70% under the age of 18, 8.20% from 18 to 24, 32.40% from 25 to 44, 22.80% from 45 to 64, and 9.80% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 97.20 males. For every 100 females age 18 and over, there were 94.20 males.
The median income for a household in the county was $67,887, and the median income for a family was $79,314. Males had a median income of $52,372 versus $35,450 for females. The per capita income for the county was $31,315. About 2.40% of families and 3.60% of the population were below the poverty line, including 3.90% of those under age 18 and 4.30% of those age 65 or over.