 Eggan's work in Santa Fe analyzed each Western Pueblo social structure and compared and contrasted them to the Eastern Pueblos.His most important contribution to archeology, and possibly anthropology in general, was his demonstrations how the variations currently observed in the Pueblo social structures are related to cultural adaptations to ecological niches.Eggan's time spent studying the Cheyenne and Arapaho served as a basis for one of his most famous works, “Social Anthropology and the Method of Controlled Comparison.” He demonstrated how it was possible for the Cheyenne to change from a predominantly agricultural based lineage type kinship system to a system that was predominantly nomadic involving a heavy dependence on hunting and gathering in bands to increase their efficiency.