Hillsboro is a city in Montgomery County, Illinois, United States. The population was 6,207 at the 2010 census. It is the county seat of Montgomery County.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.Hillsboro is located at 39°9′54″N 89°29′4″W (39.164973, −89.484572).
According to the 2010 census, Hillsboro has a total area of 8.322 square miles (21.55 km2), of which 6.55 square miles (16.96 km2) (or 78.71%) is land and 1.772 square miles (4.59 km2) (or 21.29%) is water.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 (468.8/km2). There were 1,944 housing units at an average density of 541.8 per square mile (209.1/km2). 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.
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