Architect George H. Miller designed the building, which has a medieval style resembling a castle.

The building features a central tower, multiple turrets, and a crenellated roof line.

The Old Main originally housed all of the offices and classrooms for Eastern Illinois, its library, auditorium, and gymnasium.

[2] The building was added to the National Register of Historic Places on June 16, 1981.

This article about a property in Coles County, Illinois on the National Register of Historic Places is a stub.