The Master Key System – Charles F Haanel is a personal self development course that was published in 1912, when he was 46 years old. Charles F Haanel has been heralded as the God Father of personal development with his self development course – The Master Key System. It is written in the form of a course in New Thought, mental development, financial success, and personal health. Among the key points of Haanel's system are what he refers to as the laws of concentration, attraction, and harmonious thinking and action. Unique to the Master Key System is a set of exercises that accompany each chapter, and which are systematically building upon each other – they are what makes the Master Key System a system. In addition to the Master Key System, Haanel wrote several other books including Mental Chemistry published in 1922, The New Psychology published in 1924, A Book about You published in 1927, and The Amazing Secrets of the Yogi published in 1937. In 1919, Napoleon Hill wrote Haanel a letter thanking him for The Master Key System. In the letter Hill stated, «My present success and the success which has followed my work as President of the Napoleon Hill Institute is due largely to the principles laid down in The Master-Key System." Haanel was quoted in the best-selling self-help book The Secret by Rhonda Byrne, published in 2007. The Haanel family was of Swedish extraction, but had lived in Silesia, Prussia, before emigrating to Canada and thence to the United States. In St. Louis: History of the Fourth City, the author Walter B. Stevens wrote that «Charles F. Haanel was born in Ann Arbor, Michigan, the son of Hugo and Emeline (Fox) Haanel." He was the fourth of six children. According to Stevens, «The family moved to St. Louis, Missouri when Charles was a child. His first job was as an office boy for the National Enameling & Stamping Company in St. Louis, and he worked for this firm in varying capacities for fifteen years before striking out on his own.