Into the Wild, the book based on Christopher McCandless’ life was written by Jon Krakauer and published in 1996. In 1993 Jon had written an article about Christopher for the Outsider magazine. The immense response that Krakauer received for the article motivated him to delve deeper into the life of Chris and this resulted in the book.
Krakauer made all attempts to ensure the facts which form the basis of the book were accurate. These were collected by meeting hundreds of people which included family members, friends, colleagues and many others who had come across Chris while he was on his adventure that finally ended with his death in Alaska. Krakauer personally visited the locations where Chris had been to get familiar with the environment where he spent his days.
An important aspect that helped Krakauer connect to Chris’ life was his own ambition and several attempts made to spend time in the wilderness detached from others. The marked similarity of their lives is reflected in his words
I got away with it. Chris didn't. That's the only difference.