Plainville is a village in Adams County, Illinois, United States. The population was 264 at the 2010 census. It is part of the Quincy, IL - MO Micropolitan Statistical Area.HistoryPlainville was originally called Stone's Prairie after Samuel Stone who settled here in 1822.In the 1860 presidential election campaign, Plainville was the site of a political rally involving around 7,000 people. This resulted in the "Stone's Prairie Riot" on August 25, 1860, at which the Republican Party para-military organization, the "Wide Awakes", confronted armed supporters of the Democratic Party.GeographyPlainville is located at .According to the 2010 census, Plainville has a total area of 0.23sqmi, all land.DemographicsAs of the census of 2000, there were 248 people, 100 households, and 74 families residing in the village. The population density was 1,078.7 people per square mile (416.3/km²). There were 110 housing units at an average density of 478.5 per square mile (184.7/km²). The racial makeup of the village was 99.60% White, and 0.40% from two or more races.There were 100 households out of which 35.0% had children under the age of 18 living with them, 61.0% were married couples living together, 8.0% had a female householder with no husband present, and 26.0% were non-families. Of all households 22.0% were made up of individuals and 12.0% had someone living alone who was 65 years of age or older. The average household size was 2.48 and the average family size was 2.84.
