The untold story of 'Mary Poppins' shared in special edition of '20/20'

It's been 60 years since the Disney classic "Mary Poppins" first floated into our lives.

For a while, making the film seemed like an impossibility for Walt Disney. He pursued the film rights from the author, P.L. Travers, for almost three decades.

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An ABC News two-night event commemorates the film's anniversary with rarely-seen video and stories, and chronicles its turbulent flight from children's book to the silver screen.

Watch "The Untold Story of Mary Poppins: A Special Edition of 20/20" on Wednesday at 9/8c and the the Wonderful World of Disney presentation of "Mary Poppins" on Thursday 8/7c on ABC.

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