Systems of Consanguinity and Affinity of the Human Family

Having discovered that the typical European way of organizing kin relations was not universal, Morgan came to suspect that other languages in the Americas and perhaps in Asia had similar systems and began an investigation.

[7] Upon reaching Sioux City at the end of his 1862 field season he learned that his daughters Mary and Helen Morgan (2 and 6 years old respectively) had died of scarlet fever almost a month earlier.

The delay was due to the book's undergoing two rounds of peer review, a precaution taken by the agent of publisher Joseph Henry whose Smithsonian Institution was heavily invested in the publication.

Morgan, a lawyer by profession, estimated that the effort of researching, writing, and producing the book cost him 25,000 dollars in expenses and lost profits.

[9] Although copies of the manuscript had been circulating among the reviewers and other scholars already in 1870, the book was finally published in 1871 as the seventeenth volume of the Smithsonian's "Contributions to Knowledge" series.

Based on this idea of progressive improvement of systems of social organization, he argued that the primeval form of kinship among the earliest humans was a kind of "primitive promiscuity" in which everyone was considered equally related to everyone in their group because there was no knowledge of preferential partnerships, and even siblings married each other.

Karl Marx read both Systems and Morgan's subsequent book Ancient Society (1877) which built on and extended the arguments of the previous one.

Posthumously, Marx' notes on Ancient Society were edited by Friedrich Engels and published as The Origin of the Family, Private Property and the State.

Much of the earliest work in anthropology was aimed at refuting Morgan's central theses about social evolution, primitive promiscuity, and group marriage.

Rivers' student A. R. Radcliffe-Brown was also highly critical of Morgan, but had an extensive knowledge of Systems of Consanguinity which he used as a basis for his own seminal studies of Native American kinship patterns.

[17] Anthropologists have generally agreed that Morgan's main discovery was the fact that kinship terminology has relevance to the study of human social life.