The City Center Historic District is significant for its portrayal of the economic growth and development of the city, and for its architecture as a showcase of late 19th and early 20th century commercial styles. Historically, during the late 19th century, Hagerstown became a leading manufacturing city and a rail center in Maryland. This resulted in a great population growth and a commercial boom period that occurred between 1880 and 1920. This economic boom is reflected in the almost total redevelopment and transformation of the downtown commercial area during that period. Large hotels catering to rail and automobile travelers were built and commercial establishments were either remodeled or newly built to reflect the prosperity. Nearly all of the buildings are representative of popular commercial styles of the turn of the century.

The favored architectural expression was the Italianate style consisting of two and three story buildings with prominent bracketed cornices; elaborate Baroque and Neoclassical forms associated with the Beaux Arts style; and a very simple early 20th century commercial style featuring strongly rectilinear forms. Pivotal buildings in the district are the Washington County Court House and the Hagerstown City Hall which helped to establish the direction of commercial growth along West Washington and North Potomac Streets.

Significant historic resources in the district include the Maryland Theatre, First Hose Fire Company, Colonial Theater, Masonic Temple, Barnwood Books Building, St. John's Lutheran Church, Kohler Building, Baldwin House, Routzahn's Department Store Building, Delta Building, the Courthouse, the Miller House, Kneisley Building, the Old Library, the Roslyn, 119 N. Potomac Street, the Pioneer Hook & Ladder Firehouse, the Knights of Pythias Castle, the Post Office, Grunnell Building, Wolf Building, and Thomas Building.