As an ethnologist and early anthropologist, Powell was a follower of Lewis Henry Morgan. He classified human societies into ‘savagery’, ‘barbarism’, and ‘civilization’. Powell's criteria were based on consideration of adoption of technology, family and social organization, property relations, and intellectual development. In his view, all societies were to progress toward civilization. Powell is credited with coining the word “acculturation”, first using it in an 1880 report by the U.S. Bureau of American Ethnography. In 1883, Powell defined “acculturation” as psychological changes induced by cross-cultural imitation.