For almost 200 years Rockland, Maine?s principal commercial thoroughfare has been the densely built Main Street. The street is lined with brick or frame, one, two and three story stores, banks, offices and other commercial structures in architectural styles including the Greek Revival, Italianate, Classical Revival, Colonial Revival and Commercial style. Nineteenth- and early twentieth-century buildings are found all along the street, but the greatest concentration of buildings with historic integrity are located in the northern two-thirds of the commercial district. The Main Street Historic District Boundary Increase builds upon the original Main Street Historic District listed in the National Register of Historic Places in 1978. The purpose of the recent nomination was to provide additional descriptive information on the properties previously listed and to increase the boundaries to include twelve additional buildings in the northerly section of the downtown business district. These buildings are contiguous to the existing district and are of significant importance to the economic, social, civic and commercial history of downtown Rockland. Together, with the original district, they form a cohesive group of commercial buildings built between 1848 and 1941. This period coincides with the height of Rockland?s prosperity resulting from commerce, industry and a burgeoning population.