Like its contemporaries the Gothic Revival and Italianate, the Second Empire was a modern interpretation of earlier architectural forms. The Second Empire style was re-introduced by Napoleon III of France, who constructed several monumental buildings in the mid-19th century that incorporated the mansard roof, a Medieval French feature. Second Empire residential architecture appeared in the United States almost immediately after the Civil War and was particularly common throughout the 1870s. The key feature of the style is the mansard roof, a "requirement" for a building to be considered part of the style. However, other features are also common, such as decorative iron cresting along the ridge lines; a heavy cornice that incorporated an interior gutter system supported by heavy brackets and/or consoles; tall windows that often featured arched heads; multiple dormers on the third floor; and use of thick molding on doors and window surrounds. A major advantage of the mansard roof is that it made the upper level far more useable in an affordable manner (than a typical attic). The house at 306 West 9th Street in Erie (above) illustrates many of these features.
A grouping of Second Empire houses along West 6th Street in the City of Erie represents a subset cluster. These houses feature large hexagonal bays on the main elevation flanking a recessed entrance atop a flight of stairs. Examples were found at 328, 332-334, and 462 West 6th Street, all within the West Sixth Street Historic District. The survey identified several other Second Empire houses of exceptional quality, such as the house at 527 West 6th Street, also in Erie. A block of Second Empire style rowhouses was identified at 201-205 West 8th Street in Erie, and a rather unusual 2-story Second Empire house was identified at 329 West 9th Street in the city.