Orison Swett Marden (January 16, 1850 – October 24, 1924) was an American author, editor, self-improvement enthusiast and publisher. He wrote a series of books and essays focussing on personal development and spiritual growth. He believed in the power of attitude, enthusiasm and hard work to achieve success and popularity of his works made Marden one of the first best-selling authors in the self-help genre.

Charles F. Haanel (May 22, 1866 - November 27, 1949) was an American author and success coach known for his best-selling books 'The Master Key System’, ‘The Law of Success’ and 'Outwitting the Devil'. He was once called the Napoleon Hill of his time and his books have inspired millions of people to make positive changes in their life and become successful.

Elsie Lincoln Benedict (1885–1970) was advertised as the best-known women's speaker during the 1920s, speaking to over 3 million people in her lifetime and writing on what Napoleon Hill and Dale Carnegie and a long list of men would do later. She was an American suffragist leader, and founder of Brainology. She was also an influential figure in the fields of personality analysis and human behavior, and greatly contributed to the foundation of modern personality assessment methodologies.

Elbert Hubbard (June 19, 1856 – May 7, 1915) was an American writer, publisher, artist, and philosopher. He was an advocate of the Arts and Crafts movement and is widely known for his publication of the popular “Roycroft” books, works of literature devoted to self-improvement and personal growth. He is also remembered for his inspirational essay “A Message to Garcia”, a piece of writing that encouraged perseverance against all odds.