It is the History of Herkimer County by Nathaniel S. Benton, 1856.
Benton writes, "One of the strongest inducements that led me to undertake the task which I have now completed, was to correct as far as I could, some of the grave, and it seemed to me manifest errors or mistakes, which found their way into published works of supposed authenticity, in regard to General Nicholas Herkimer and his family. No author ever spoke of him, to my knowledge, as a brilliantly great man, and no one can with justice or propriety deny that he was a brave and good man; firmly devoted to the provincial cause and American freedom. If a cloud appeared in the distance to hang over him, growing out of the fact that some members of the family were hostile to the movements of the colonists, could it be any fault of his, unless he had the ability to control them, and failed to exert it? But let it be remembered that other members of the same family who survivedthe General, devoted themselves in the future progress of the war, with zeal and courage in defense of the country."
Further down: "We are not only able to name the first European settlers, the pioneers of the upper valley, but we can trace the descendants of most of them, as being still inhabitants of the county, while some of those families, from emigration or othercauses have become entirely extinct, and the name is no longer known among us. Although there now are numerous descendants of the female branch of the Herkimer family in the county, it is believedthere is not, at this time, one inhabitant in it bearing that name."
So we may have to contact the Herkimer Home Historic for lists of Herkimer descendants, and I'm going to check Ontario and Quebec, too, as it sounds as if many of these folks headed north. Certainly there were NO Herkimers listed in the Herkimer County Directory of 1869-70, and I feel certain they are all related.