In 1868, Henry Varnum Poor established H.V. and H.W. Poor Co. with his son, Henry William Poor, and published two annually updated hardback guidebooks, Poor's Manual of the Railroads of the United States and Poor's Directory of Railway Officials.
Pada tahun 1868, Henry Varnum Poor dan anaknya, Henry William Poor mendirikan H.V. and H.W. Poor Co., perusahaan ini menerbitkan dua buku yang terbit setiap tahun, yang berjudul Poor's Manual of the Railroads of the United States dan Poor's Directory of Railway Officials.