Sanderson joined the Suffield (Conn.) Academy staff in 1952, where he taught American history and coached soccer, basketball and tennis. He also served as Suffield’s Director of Admissions and Assistant Headmaster. During his four years as Headmaster he brought co-education to the school and expanded its performing and creative arts programs. He had a 156-77-22 record in 22 years as soccer coach. In 1969 he founded the American Secondary Schools for International Students and Teachers (ASSIST).

His efforts to grow the sport branched in several directions. Founder and president of the Western New England Preparatory School Soccer Association, he also was president of the NASL’s Hartford Bicentennials from 1974-76. A vice-president of the NSCAA, he received two Letters of Commendation from the association, recognizing his coaching success, organizational efforts for prep school soccer and his work to attract independent and high school coaches into the NSCAA.