The Hamilton Primary School is a two story, stone, italianate building constructed in 1873 in the small town of Otterville, in south-central Jersey County, Illinois. The school is approximately 4,560 square feet. It is located about 200 feet northeast of the "four corners" in Otterville, which is the crossroads of Otterville and McClusky roads. The school sits on approximately one-half acre with the front facade facing south onto McClusky Road (Main Street). A modern, one-story building which was built in the 1950's for additional classroom space, is located to the east of the school. This building is now owned by Illinois Valley Economic Development Association. The Otterville Baptist Church is located west of the school. The surrounding land is basically level and several modern homes and outbuildings lies immediately south of the school. The land surrounding Otterville is devoted to agriculture.
The school is basically a T-shape with small hipped roof extensions. The front facade faces south and displays a magnificent front entrance with paired arched windows and double doors leading into the school. The doors, located in the center of the facade, are partially covered with a flat roof. The rough-cut stone is set in regular courses. The limestone foundation extends over five feet below ground level and four feet above. All exterior walls are stone. Two chimneys rise from the interior of the school though the gabled standing seam metal roof. They are located at the ends of the east and west wings. The cupola has four small arched louvers. There are 33 additional windows with four small arched and rectangular lintels. Most of the windows are four-over-four.