William Graham Sumner (October 30, 1840 – April 12, 1910) was a classical liberal American social scientist. He taught social sciences at Yale, where he held the nation's first professorship in sociology. He was one of the most influential teachers at Yale or any other major school. Sumner wrote widely within the social sciences, with numerous books and essays on American history, economic history, political theory, sociology, and anthropology. He supported ''laissez-faire'' economics, free markets, and the gold standard. He adopted the term "ethnocentrism" to identify the roots of imperialism, which he strongly opposed, and as a spokesman against it he was in favor of the "forgotten man" of the middle class, a term he coined. He had a long-term influence on conservatism in the United States.