The eight editions of Gray's Manual are overviewed, with special attention being given to the first six, the editions in which Asa Gray was sole author (editions one through five) or co-author (edition six). Changes to the editions are summarized and reviews, positive in the beginning and more critical later with the sixth edition, are discussed. While Gray himself admitted that he failed in his effort to make the Manual a vade mecum he did succeed in providing an excellent identification manual for the region in a single volume. This Manual would be used by almost all students of the flora's region, including those who would criticize later editions when it did not keep up with all of the botanical discoveries that were occurring in the Manual's range.