Benjamin Cohn, Harvey's grandfather, practiced architecture at an exciting time which saw a massive movement of people to Brooklyn, many from Manhattan. Harvey located Ben's diary, which lists over 100 buildings that Ben and his brother, as partners in their architectural firm, designed and built. Most were variations on a design for a large apartment complex of six-story masonry construction, with an "H" shaped footprint. Many still stand today. Interestingly, this seems to have been before street addresses in Brooklyn were finalized — many of the projects listed in the diary refer merely to street corners and to measured lengths from them.