one example; Nathan Allen & Mary Putnam are my gggg-grandparents, and the book below was written by Nathan Allen's brother, Augustus Lovanzo Allen.
ab00183 ALLENBrief history of the family of Nathan Allen and Mary Putnam, his wife, late of Ft Plain, Montgomey Co., NY, and of the families of Rev. Aaron Putnam of Pomfret CT, the Bulkeley, Prescott,Hall, Grosvenor and other families with which the Allen family were connected,by A.L. Allen. 132p. 1895.