First constructed in 1766 by John Harris Jr, the Mansion was built with locally quarried limestone. Simon Cameron, Lincoln's first Secretary of War and then Minister to Russia, purchased the Mansion during the Civil War. He converted the building to a grand Victorian Mansion in the Italianate style. Additions included a solarium, walkway, butler's pantry and grand staircase. The last of Simon Cameron's relatives lived in the Mansion until 1933. The family donated the house to the Historical Society of Dauphin County in 1941. Guided tours of the Mansion are available for individuals or groups. The first floor of the Mansion can also be rented for events.