While many urban histories take as their point of departure the works of “great men” or the reflections of American culture though the urban experience, still others examine the influence of technical achievements on urban life. Among the most notable of this latter type is Sam Bass Warner’s,StreetCarSuburbs. Ofcourse,Warner’sbookbeginswiththe manipulation of technology by commercial institutions and ends with theadaptationofurbandwellerstoanewresidentialinstitution. Through- out, the treatment of the material urban form – in this case the physical suburb – seldom transcends generalization. Here enter Mary Ellen Hay- ward and Charles Belfoure in their painstaking treatment of The Balti- more Rowhouse.