These three maps [16, 17, 18] were produced as fold-outs to be inserted in Portland city directories first published in 1823. The first map in this series , produced by Abel Bowen, became the benchmark against which future directory maps were measured. The waterfront and Back Cove were little changed from Colonial days, with Back Cove extending to Oxford Street and Cumberland Avenue and the waterfront at Fore Street. The many streets laid out in the west end were still unbuilt. Eight years later, the 1831 edition of the directory map  by David C. Johnson, eliminates the yet-to-be realized streets in the west end as laid out on the Bowen map and adds only modest changes for the intervening years. The 1852 plan  published by S. H. Colesworthy shows dramatic changes in just twenty one years. Back Cove was filled by Charles Q. Clapp, creating an area for real estate development and railroad expansion. By 1851, the waterfront had moved outward as the city built Commercial Street at a cost of $80,000. Few of the Munjoy Hill and the West End streets were were actually constructed as proposed here on this map.