Reminiscence is of course, standing alone, an insufficient basis for historical generalization. On that point Professor Siebert has been careful to explain his principle: he does not attempt to generalize from single memories not otherwise substantiated, but to use reminiscences which confirm each other, to search out telling illustrations, and to discover what the tendencies were from numerous contrasted testimonies. Actual contemporary records are scanty; a few are here preserved, such as David Putnam's memorandum, and Campbell's letter; and the crispness which they give to the narrative makes us wish for more. The few available biographies, autobiographies, and contemporary memoirs have been diligently sought out and used; and no variety of sources has been ignored which seemed likely to throw light on the subject. The ground has been carefully traversed; and it is not likely that much will ever be added to the body of information collected by Professor Siebert. His list of sources, described in the introductory chapter and enumerated in the Appendices, is really a carefully winnowed bibliography of the contemporary materials on slavery. The book is practically divided into four parts: the Railroad itself (Chapters ii, v); the railroad hands (Chapters iii, iv, vi); the freight (Chapters vii, viii); and political relations and effects (Chapters ix, x, xi). Perhaps one of the most interesting contributions to our knowledge of the subject is the account of the beginnings of the system of secret and systematic aid to fugitives. The evidence goes to show that there was organization in Pennsylvania before 1800; and in Ohio soon after 1815. The book thus becomes a much-needed guide to information about the obscure anti-slavery movement which preceded William Lloyd Garrison, and to some degree prepared the way for him; and it will prove a source for the historian of the influence of the West in national development. As yet we know too little of the anti-slavery movement which so profoundly stirred the Western states, including Kentucky and Missouri, and which came closely into contact with the actual conditions of slavery. As Professor Siebert points out, most of the early abolitionists in the West were former slaveholders or sons of slaveholders.