McHenry is a city in McHenry County, Illinois, United States. The 2010 U.S. census reported its population at 26,992. McHenry was at one time the county seat of McHenry County, which once included adjoining Lake County to the east. McHenry was named for Major William McHenry, an Indian fighter.
McHenry is surrounded by natural lakes and streams, grassy moraine hills, gravel banks and shallow nutrient-rich peat bogs, remnants of receding glaciers from the last ice age. Moraine Hills State Park and Volo Bog State Natural Area preserve some of these unique natural features.
McHenry is located 50 miles northwest of Chicago in northern Illinois on the Fox River. According to the 2010 census, the city has a total area of 15.18 square miles (39.3 km2), of which 14.74 square miles (38.2 km2) (or 97.10%) is land and 0.44 square miles (1.1 km2) (or 2.90%) is water. McHenry lies within the watershed of the Fox River, and its downtown area is situated on that river.
There were 7,872 households of which 38.7% had children under the age of 18 living with them, 57.2% were married couples living together, 9.7% had a female householder with no husband present, and 29.4% were non-families. 24.7% of all households were made up of individuals and 9.9% had someone living alone who was 65 years of age or older. The average household size was 2.70 and the average family size was 3.25.
Age distribution was 28.5% under the age of 18, 7.8% from 18 to 24, 32.7% from 25 to 44, 19.9% from 45 to 64, and 11.0% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 94.8 males. For every 100 females age 18 and over, there were 91.2 males.
The median household income was $55,759, and the median family income was $66,040. Males had a median income of $46,552 versus $29,808 for females. The per capita income for the city was $23,272. About 3.8% of families and 4.6% of the population were below the poverty line, including 6.1% of those under age 18 and 2.6% of those age 65 or over.
Major industrial users including Medela, Follett Library Resources, Fabrik Industries and Plaspros have located in the city's business parks. Centegra's Northern Illinois Medical Center (NIMC) campus calls McHenry home and provides emergency and in and out-patient health care services to the City and surrounding areas. Steady residential growth has resulted in significant commercial development. The north Richmond Road corridor has become a destination for shoppers in the northern Illinois and southern Wisconsin areas with numerous "big box" retailers and smaller chains. The City has also been very diligent and active in preserving, promoting and revitalizing its three downtown districts: Main Street, Green Street and Riverside Drive.