Despite or perhaps because of its isolated location, Mercersburg Academy is the principal architectural destination of Franklin County, attesting in its varied buildings to an institution with national aspirations. The campus began as a single cupola-crowned building for Marshall College, perhaps based on Dickinson College's Old West (CU10.1). Burned in the 1920s, Main Hall was rebuilt along the original lines but apparently missed many of the grace notes of the original building. It terminates Seminary Street and sets the tone for a Colonial Revival cluster of buildings in the front range of buildings. With the removal of Marshall College (in 1853; LA24) and the German Reformed seminary to Lancaster (in 1871; LA25), the institution languished until it was transformed under the leadership of William Mann Irving in the 1890s. The campus is split between Colonial Revival buildings and those in the Gothic style. Philadelphians Day and Klauder, who designed Colonial Revival buildings at Franklin and Marshall and Penn State, and Gothic buildings at Princeton and Wellesley, were the architects for towered Gothic Nolde Gymnasium (1912–1914; 1967 alterations) and Traylor Hall (FR10.3).

Under the direction of Charles Klauder, the orientation of the campus shifted both spatially and architecturally to multiple centers, with the old campus at the entrance, a residential and athletic campus to the rear, and the ceremonial campus—the so-called front campus—that is framed by the new administration building on the west, Rutledge Hall on the east, and terminates in Irvine Memorial Chapel (
FR10.4
). More recent architects come from the nation's northeast, attesting to the school's national audience.