Charter Oak School is said to be the only octagonal one-story brick schoolhouse in Illinois. It was built in 1873 in accordance with a design suggested by Daniel Ling, a teacher of the Charter Oak School district, and it served as a school until 1953. Its octagonal shape utilizes daylight and offers wind resistance. The first school in the district was a log building, erected three years after the Illinois Free School Law was passed in 1845. This was succeeded in 1863 by a frame structure in which Ling taught in 1872-1873.