Stevens believed that character and self‑discipline were as important as a sound academic background for the development of young men. He did not believe in rigid, unmodifiable educational planning and was open to many ideas that would improve academic performance.  In 1935, he retired from Cranbrook due to ill health. Following a period of recuperation, he accepted a position as the acting dean of the College of Literature at Oglethorpe University. He left that position after one year and devoted the rest of his life to writing and illustrating articles and books, primarily on travel and psychic phenomena.Stevens authored more than 45 books. His work included multi‑biographies for young adults, such as Famous Men of Science and Famous Women of America. He also authored local histories, including: Old Williamsburg and Her Neighbors; Charleston, Historic City of Gardens; Annapolis, Anne Arundel's Town, and others. His earliest works included satiric verse and illustrations: An Annapolis Alphabet (1906) and "The Strike at Santa Claus" for St. Nicholas Magazine (December 1907). After the death of his son Mason, Stevens’s writings became increasingly philosophic and somewhat mystical. He published The Mystery of Dreams in 1949 and Psychics and Common Sense in 1953. William Oliver Stevens died in his sleep at his Manhattan home on January 15, 1955.