William Graham Sumner was an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 academic and "held the first professorship in sociology

Sociology

Sociology is the study of society. It is a social science—a term with which it is sometimes synonymous—which uses various methods of empirical investigation and critical analysis to develop a body of knowledge about human social activity...

" at Yale College

Yale College

Yale College was the official name of Yale University from 1718 to 1887. The name now refers to the undergraduate part of the university. Each undergraduate student is assigned to one of 12 residential colleges.-Residential colleges:...

. For many years he had a reputation as one of the most influential teachers there. He was a polymath

Polymath

A polymath is a person whose expertise spans a significant number of different subject areas. In less formal terms, a polymath may simply be someone who is very knowledgeable...

 with numerous books and essays on American history, economic history

Economic history

Economic history is the study of economies or economic phenomena in the past. Analysis in economic history is undertaken using a combination of historical methods, statistical methods and by applying economic theory to historical situations and institutions...

, political theory, sociology

Sociology

Sociology is the study of society. It is a social science—a term with which it is sometimes synonymous—which uses various methods of empirical investigation and critical analysis to develop a body of knowledge about human social activity...

, and anthropology

Anthropology

Anthropology is the study of humanity. It has origins in the humanities, the natural sciences, and the social sciences. The term "anthropology" is from the Greek anthrōpos , "man", understood to mean mankind or humanity, and -logia , "discourse" or "study", and was first used in 1501 by German...

. He is credited with introducing the term "ethnocentrism

Ethnocentrism

Ethnocentrism is the tendency to believe that one's ethnic or cultural group is centrally important, and that all other groups are measured in relation to one's own. The ethnocentric individual will judge other groups relative to his or her own particular ethnic group or culture, especially with...

," a term intended to identify imperialists' chief means of justification, in his book Folkways (1906).