At the 2000 census there were 12,944 people in 5,353 households, including 3,377 families, in the city. The population density was 2,062.1 people per square mile. There were 5,879 housing units at an average density of 936.6 per square mile. The racial makeup of the city was 90.27% White, 3.68% African American, 0.06% Native American, 0.35% Asian, 0.02% Pacific Islander, 3.69% from other races, and 1.95% from two or more races. Hispanic or Latino of any race were 6.10%. Of the 5,353 households 28.5% had children under the age of 18 living with them, 47.0% were married couples living together, 12.3% had a female householder with no husband present, and 36.9% were non-families. 32.2% of households were one person and 17.7% were one person aged 65 or older. The average household size was 2.38 and the average family size was 2.98. The age distribution was 24.8% under the age of 18, 8.9% from 18 to 24, 25.4% from 25 to 44, 20.5% from 45 to 64, and 20.5% 65 or older. The median age was 38 years. For every 100 females, there were 88.8 males. For every 100 females age 18 and over, there were 84.7 males. The median household income was $29,895 and the median family income was $37,730. Males had a median income of $29,065 versus $19,792 for females. The per capita income for the city was $15,746. About 10.7% of families and 13.9% of the population were below the poverty line, including 21.0% of those under age 18 and 8.9% of those age 65 or over.
2010 census
According to the 2010 census, the city had a population of 12,916. Of this, 11,241 were white, 633 were black or African American, 624 were some other race, 325 were two or more races, 51 were Asian, 38 were American Indian or Alaska Native. 1,350 were Hispanic or Latino of any race.
Industry
Kewanee was once known for its fire-tube boiler industry. The Kewanee Boiler Corporation manufactured and sold boilers throughout the world for over one hundred years. The company shuttered in 2002, however, boilers manufactured in Kewanee are still in common use. The Kewanee High School athletic teams are nicknamed the "Boilermakers". Kewanee was home to minor league baseball. The Kewanee Boilermakers minor league baseball team played in the Central Association from 1908–1913. In 1948–1949, the Kewanee A's rejoined the Central Association. Kewanee was an affiliate of the Philadelphia Athletics. Kewanee minor league teams played at Terminal Park and Northeast Park.
Parks
Kewanee has many different types of parks in the immediate area, offering a variety of activities such as boating, camping, hunting, fishing, playgrounds, baseball fields, and more. Parks inside the city limits are run by the Kewanee Park District.
Schools
Kewanee has had two school districts, dating to when the community of Wethersfield was a separate municipality. Though the towns merged long ago, the two school districts both remain in the city of 13,400, divided at Division Street in the middle of Kewanee. While Kewanee School District #229 has around 2,015 students, Wethersfield #230 has about 600 students. The two schools enjoy a usually friendly rivalry, since both district high schools are in different divisions for most sports. However, this rivalry did become very heated in the sports the two high schools once competed in, most notably basketball. There are also other schools in Kewanee like Visitation Catholic School: home of the Giants, and a community college, Black Hawk College. Black Hawk College-East Campus is recognized nationally for its equestrian program, as well as livestock judging teams.
Festivals
The most notable festival held in the community is Hog Days. It is held annually on Labor Day weekend. Events include a carnival, mud volleyball, a parade, and more.
