Charles F. Haanel was a noted American author and businessman. He began his career in St. Louis, and eventually started his own company which grew to be one of the largest conglomerates of his time. He wrote several books based on the ideas and methods he used to gain his success, including "Mental Chemistry," and "The New Psychology." By 1933 "The Master Key" had sold over 200,000 copies. Walter B. Stevens described Mr. Haanel as "A man of mature judgement, capable of taking a calm survey of life and correctly valuing its opportunities, its possibilities, its demands and obligations."