CARL ORTWIN SAUER was one of the most influential American geographers. Throughout his long and distinguished career, he shaped and fundamentally changed the field of cultural and anthropogeography in the United States. Sauer was of German descent, and his ancestors were members of a German pietistic sect affiliated with the Methodists who had settled in Warrenton, Missouri, Sauer’s place of birth. After spending a few school years in Germany, he received an A.B. degree in 1908 from Central Wesleyan College in Warrenton. In 1915 Sauer obtained his Ph.D. from the University of Chicago, where he studied with R.D. Salisbury and Ellen Churchill Semple. The latter represented the American version of environmental determinism (also referred to as "environmentalism" or “geographic influences”), then the guiding principle of American geography. Although Sauer had enjoyed Semple’s lectures at Chicago, he became increasingly dissatisfied with environmental determinism for it focused rigidly, solely, and in a Darwinian manner on the environmental influences on man.