This is an update survey which maps the key features of naturalism as one of the central conceptions in American philosophy. Following the introduction with brief remarks on the current “naturalistic turn”, the author follows up with an overview of the development of American naturalism indicating its key figures and schools as well as its key features such as realism, non-reductionism and pluralism. He then focuses on naturalism of classical pragmatism. Based on an account of Peirce, James and Dewey and their contributions, the specific characteristics of their versions are given such as anti-authoritarianism (anti-absolutism), anti-dualism, and humanism. The classical pragmatist naturalism is “cultural naturalism” overcoming the gulf between nature and culture. Its central concept is the concept of human cultural practices encompassing human transactions with nature and human creation of cultural forms.