Disney's Peter Pan is based on Sir James Barrie's play "Peter Pan" (1904) and his subsequent book versions of that famous story. To gain insight into what Barrie had in mind beyond the actual dialogue and scene description, Disney used Barrie's original play notations. These notes were not only stage directions that he scribbled during play rehearsals, but his own concepts of the characters and their reactions to magical events unfolding before them.
When Walt and his brother Roy were children, they robbed their piggy banks to scrape together enough money to watch a road company performance of Peter Pan on stage. It was then that Walt became so fond of the story of the boy who wouldn't grow up. Not long after, Walt played Peter Pan in his school play.
There are a number of differences between the stage and the screen Peter Pan, the most significant of which is the casting of the title character. Prior to the film, Peter had always been played by a young woman, but Disney chose to portray him as a twelve year old boy. Walt explained the age plainly saying, "He is twelve years old forever simply because he refuses to grow up beyond that comfortable age". The other differences were of course provided by the magic of animation.
Although firmly established in legend, the figure of Tinker Bell is not based on Marilyn Monroe. Tinker Bell owes her shapely form to the "Pin-Up Girls" of World War II like Betty Grable and others. Monroe was still a supporting actor and a relative unknown at the time Tinker Bell was developed. A woman named Margaret Kerry was Tinker Bell's live-action reference model.
By the time of its 1953 release, Peter Pan had been in development at Disney for 14 years. Disney had purchased the film rights to the story in 1939.
Tinker Bell continued her Disney career as the introductory icon on decades of Disney television programs, as well as introducing spectacular fireworks displays at Disney theme parks. In the J.M. Barrie play, Peter Pan, or The Boy Who Wouldn't Grow Up, Tinker Bell was just a projected beam of light.