Think and Grow Rich is a book written by Napoleon Hill in 1937 and promoted as a personal development and self-improvement book. He claimed to be inspired by a suggestion from business magnate and later-philanthropist Andrew Carnegie. First published during the Great Depression, the book has sold more than 15 million copies It remains the biggest seller of Napoleon Hill's books. BusinessWeek magazine's Best-Seller List ranked it the sixth best-selling paperback business book 70 years after it was published. Think and Grow Rich is listed in John C. Maxwell's A Lifetime "Must Read" Books List.