Finally, returns from his schedules of inquiry began to pour in from all quarters of the globe, and gradually a vast correspondence grew up, until the kinship systems of more than four fifths of the world were recorded either directly by himself or by others whom he had enlisted in the work. The materials thus collected were gradually by years of labor thoroughly systematized, and finally published by the Smithsonian Institution as one of its "Contributions to Knowledge," entitled "Systems of Consanguinity and Affinity of the Human Family." It is a quarto volume of about six hundred pages, the result of many years of patient and well-directed labor, and it constitutes a model of inductive research. The kinship systems of eighty tribes of North America, together with those of a great number of the principal nations and tribes of the Old World and the islands of the sea, are fully and elaborately recorded in its tables.
This publication marks a most important epoch in anthropologic research. Prior to its appearance, the social and governmental institutions of mankind antecedent to the evolution of civilization were to a large extent unknown. Travelers and various persons more or less familiar with tribal life had put on record many curious facts, and the compilation of these facts by scholars had resulted in the accumulation of incoherent and inconsistent materials about which more or less crude and fanciful speculations were made; but the essential characteristics of tribal society, as based upon kinship in barbarism and upon communal marriage in savagery, were unknown.
This first volume was essentially a volume of facts, and only a brief and rather unsatisfactory discussion of the facts was undertaken. Mr. Morgan's final conclusion and philosophic treatment of the subject were reserved for a subsequent volume.
During the earlier years of Morgan's work upon the "Systems of Consanguinity and Affinity," he carried on an extensive law business, and was engaged in a railroad enterprise upon the Michigan Peninsula. The latter necessitated frequent visits to what was then a forest wilderness on the shores of Lake Superior, and here he became interested in the study of the beaver, which resulted in the publication, in 1868, of a volume entitled "The American Beaver and his Works." In his preface to this volume Mr. Morgan thus describes the circumstances under which these studies were made:
