Long known as one of the nation's wealthiest counties, DuPage County has transformed itself from a primarily agricultural economy to one rich in many different types of commerce. Today, DuPage County boasts a personal per capita income which is the highest in the state. DuPage County's per capita income is also the highest in the midwest; nineteen of the county's towns have average household incomes of over $100,000.
The most populous municipality within DuPage County is Naperville. The next largest communities are Wheaton and Downers Grove. A small portion of the City of Chicago is located within the county limits; however, this area is primarily commercial and as of recent census estimates, has only 230 residents.
2010 - 960,516 2000 - 904,161 1990 - 781,666 1980 - 658,835 1970 - 491,882 1960 - 313,459 1950 - 154,599 1940 - 103,480 1930 - 91,998 1920 - 42,120 1910 - 33,432 1900 - 28,196 1890 - 22,551 1880 - 19,161 1870 - 16,685 1860 - 14,701 1850 - 9,290 1840 - 3,535
As of the 2000 United States Census, there were 904,161 people, 325,601 households and 234,432 families residing in the county. The population density was 2,710 inhabitants per square mile (1,050 /km²). There were 335,621 housing units, at an average density of 1,006 inhabitants per square mile (388 /km²). 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. 17.3% were of German, 11.8% Irish, 11.0% Italian, 9.8% Poles and 5.1% English ancestry according to the Census. 79.3% spoke English, 7.7% Spanish, 1.5% Polish and 1.2% Tagalog as their first language.
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 $75,128 and the median income for a family was $89,402. Males had a median income of $60,909 versus $41,346 for females. The mean or average income for a family in DuPage County is $110,975, according to the 2005 census. The per capita income for the county was $36,532. 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.
Aside from the part of O'Hare International Airport that lies in the county, DuPage also has many railroads and several small airports, including DuPage Airport. DuPage is served by the Pace bus system.
North-south roads (from west to east) include: Illinois Route 59 (Sutton Road); Illinois Route 53 (Rohlwing Road); Interstate 355 (the North-South Tollway) and Illinois Route 83 (Kingery Highway). East-west roads (from south to north) include: Interstate 55 (Stevenson Expressway); Interstate 88 (East-West Tollway; U.S. Route 34 (Ogden Avenue); Illinois Route 56 (Butterfield Road); Illinois Route 38 (Roosevelt Road); Illinois Route 64 (North Avenue); Army Trail Road; U.S. Route 20 (Lake Street); Illinois Route 19 (Irving Park Road) and the Elgin-O'Hare Expressway, which begins at the Thorndale Ave exit of I-290 and ends on Lake St. (U.S. Rte 20), in Hanover Park.