La Prairie is an incorporated town in Adams County, Illinois, United States. The population was 47 at the 2010 census. It is part of the Quincy, IL?MO Micropolitan Statistical Area.La Prairie is located at 408?54?N 910?9?W? / ?40.14833N 91.00250W? / 40.14833; -91.00250.According to the 2010 census, La Prairie has a total area of 0.23 square miles, all land.As of the census of 2000, there were 60 people, 24 households, and 18 families residing in the town. The population density was 268.4 people per square mile. There were 34 housing units at an average density of 152.1 per square mile. The racial makeup of the town was 100.00% White.There were 24 households out of which 29.2% had children under the age of 18 living with them, 66.7% were married couples living together, and 25.0% were non-families. 25.0% of all households were made up of individuals and 4.2% had someone living alone who was 65 years of age or older. The average household size was 2.