Built in 1839, the building is the oldest courthouse in the state which is still in use.

The courthouse was designed in the Greek Revival style and features four Doric columns at its front entrance.

Williams later (1893) constructed an addition, which included a vault and document room, on the north side of the courthouse.

[2] The courthouse was added to the National Register of Historic Places on March 4, 1975.

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