In 1906, James accepted a position at the National Refining Company in West Chester, New York. Once in the United States, he was offered an assistant professorship in chemistry by Charles Parsons, at New Hampshire College of Agriculture and the Mechanic Arts in Durham, New Hampshire. Founded in 1866 by chemist Ezekiel Dimond, the school's main focus was chemistry.  Parsons was a founder of the national American Chemical Society, and Parsons and James were founding members of a national chemistry fraternity: Alpha Chi Sigma.
In 1911, Parsons moved to the U.S. Bureau of Mines. James became a full professor and succeeded Parsons as head of the chemistry department at New Hampshire College.