The Adams County Courthouse was built in 1859 to replace the original 1804 courthouse located in the town square. The new brick Italianate style building was designed to be large enough to house both the court system and county offices. The bell in the bell tower was cast in Philadelphia in 1804. The Adams County Courthouse, like most local buildings, was used as a hospital following the battle of Gettysburg in 1863. It is included on the National Register of Historic Places.

The original courtroom was in use from 1859 to 1979. The room's most striking characteristic is the tromp d'oiel frescoes painted by George Seiling in 1859. The frescoes give the illusion of ceiling support pillars encircling the room and an alcove behind the judge's bench. The Italianate suymmetry evident throughout the courtroom necessitated the use of a faux door, leading nowhere, also seen behind the judge's bench.

The frescoes and other features were restored or rectified between 1983 and 1985, with partial funding provided by a Pennsylvania Historical and Museum Commission grant. Today, the courtroom is used for ceremonial purposes only.

Visitors to the area frequently report seeing the bone-chilling apparitions of long-dead soldiers who once occupied places like the old Adams County Courthouse, where the shadow of a wounded fighter is spotted wandering the property, possibly searching for the rest of his regiment.