Passage: During 1937, Hill published the best-selling book Think and Grow Rich, which became Hill's best-known work. Hill's new wife Rosa Lee Beeland contributed substantially to the authoring and editing of Think and Grow Rich. Hill's biographers would later say this book sold 20 million copies during 50 years, although as Richard Lingeman remarks in his brief biography, "Alice Payne Hackett's '70 Years of Best Sellers' suggests the amount was considerably less."Wealthy once more, Hill re-initiated his lavish lifestyle and purchased a new estate in Mount Dora, Florida. After a few years, the couple divorced around 1940, with much of the wealth from the book going to his wife Rosa Lee Hill, leaving Napoleon Hill to start his pursuit of success once again.

Question: When was the book, Think and Grow Rich avaliable to the public?
1937