The community was founded in 1823 and incorporated on March 26, 1913. There is some doubt about the origin of the city's name. The local terrain is quite hilly, as a result of the drainage of the Shoal Creek watershed, causing widespread belief that this is the name's source. Alternatively, there is the belief that it was named for Hillsborough, North Carolina, the home of some of the early settlers, including Hiram Rountree and John Nussman.
Geography
Hillsboro is located at . According to the 2010 census, Hillsboro has a total area of, of which is land and is water.
Demographics
As of the census of 2000, there were 4,359 people, 1,800 households, and 1,189 families residing in the city. The population density was 1,214.9 people per square mile. There were 1,944 housing units at an average density of 541.8 per square mile. The racial makeup of the city was 97.22% White, 1.10% African American, 0.32% Native American, 0.37% Asian, 0.07% Pacific Islander, 0.39% from other races, and 0.53% from two or more races. Hispanic or Latino of any race were 1.19% of the population. There were 1,800 households out of which 33.1% had children under the age of 18 living with them, 50.2% were married couplesliving together, 11.9% had a female householder with no husband present, and 33.9% were non-families. 30.0% of all households were made up of individuals and 14.8% had someone living alone who was 65 years of age or older. The average household size was 2.36 and the average family size was 2.91. In the city, the population was spread out with 25.8% under the age of 18, 8.4% from 18 to 24, 27.2% from 25 to 44, 21.0% from 45 to 64, and 17.6% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 85.7 males. For every 100 females age 18 and over, there were 80.3 males. The median income for a household in the city was $33,075, and the median income for a family was $40,135. Males had a median income of $31,821 versus $18,668 for females. The per capita income for the city was $17,458. About 14.3% of families and 17.2% of the population were below the poverty line, including 24.9% of those under age 18 and 11.9% of those age 65 or over.
Protected areas
The Bremer Sanctuary, north of Hillsboro, is the southeastern terminus of the Arches Rail Trail. The 3-mile-long rail trail connects the Hillsboro area with nearby Butler.
