A large portion of this volume was written before the author realized that it had begun. In the preparation of his former book, The Soul of Abraham Lincoln, the author undertook a painstaking study of Lincoln's successive environments, which involved, incidentally, inquiry into his heredity. This latter aspect was of secondary interest, nor was the author greatly interested at the beginning in the various theories which he encountered as to Lincoln's paternity. While he made careful notes of all material which came to him in his researches, he had no occasion to utilize any of the subject matter in his preparation of the other volume, nor did he expect to write this one. A's he proceeded, however, he was surprised to find a num ber of intelligent collectors of Lincoln books and students of his history who believed that Abraham Lincoln was not the son of Thomas Lincoln. He also found that while Mrs. Hitch cock had done enthusiastic work with reference to the pater nity of Nancy Hanks, and several people had entered the lists as champions of her chastity, no one so far as he could learn had compiled the various theories adverse to Thomas Lin coln's paternity of Abraham and subjected them to a critical examination. Moreover, the author found himself at length compelled to ask of himself the question, What if these reports are true? And he pursued his investigations with an open mind, and, as he hopes and believes, in accordance with the true spirit of historical inquiry.