Montgomery County Courthouse, Hillsboro
Location within the U.S. state of Illinois
Illinois's location within the U.S.
|Named for||Richard Montgomery|
|o Total||710 sq mi (1,800 km2)|
|o Land||704 sq mi (1,820 km2)|
|o Water||6.0 sq mi (16 km2) 0.8%|
| o Estimate |
|o Density||42/sq mi (16/km2)|
|Time zone||UTC-6 (Central)|
|o Summer (DST)||UTC-5 (CDT)|
Montgomery County was formed in 1821 out of Bond and Madison counties. It was named in honor of Richard Montgomery, an American Revolutionary War general killed in 1775 while attempting to capture Quebec City, Canada. Perrin's 1882 History of Montgomery County relates that the County was named in honor of Gen. Montgomery, but goes on to say that "others are dubious as to whence it received its name."
|Climate chart (explanation)|
In recent years, average temperatures in the county seat of Hillsboro have ranged from a low of 21 °F (-6 °C) in January to a high of 91 °F (33 °C) in July, although a record low of -22 °F (-30 °C) was recorded in February 1905 and a record high of 114 °F (46 °C) was recorded in July 1954. Average monthly precipitation ranged from 2.00 inches (51 mm) in February to 4.31 inches (109 mm) in May.
As of the 2010 United States Census, there were 30,104 people, 11,652 households, and 7,806 families residing in the county. The population density was 42.8 inhabitants per square mile (16.5/km2). There were 13,080 housing units at an average density of 18.6 per square mile (7.2/km2). The racial makeup of the county was 95.1% white, 3.2% black or African American, 0.4% Asian, 0.2% American Indian, 0.5% from other races, and 0.7% from two or more races. Those of Hispanic or Latino origin made up 1.5% of the population. In terms of ancestry, 27.8% were German, 11.2% were Irish, 10.1% were English, and 9.8% were American.
Of the 11,652 households, 29.8% had children under the age of 18 living with them, 51.7% were married couples living together, 10.2% had a female householder with no husband present, 33.0% were non-families, and 28.4% of all households were made up of individuals. The average household size was 2.38 and the average family size was 2.87. The median age was 41.9 years.
The median income for a household in the county was $40,864 and the median income for a family was $56,945. Males had a median income of $40,749 versus $29,426 for females. The per capita income for the county was $21,700. About 10.9% of families and 14.0% of the population were below the poverty line, including 22.7% of those under age 18 and 7.4% of those age 65 or over.