After being rejected by P.L. Travers for more than 20 years, Walt finally paid a visit to P.L. in person to convince her to let him make her books into a movie. It was the personal visit that convinced her - she described Walt as the friendly old uncle type who hypnotized you with his gold pocket watch. Not exactly a compliment, but she gave him the rights nonetheless.
Travers specified that she wanted script approval and was notoriously picky about what she would and wouldn't allow. However, a bunch of stuff ended up getting through that she didn't like because Walt told her that she had script approval but not Final Draft approval. Among the things she wanted axed: the whole score (she just wanted period songs used), the part where the gang pops into the chalk drawing, and Mary Poppins' personality. She was apparently not as warm in Travers' stories. Travers was so upset by the changes she left the film's premiere in tears.
All of the people Bert sings to in his one-man-band sequence at the beginning are characters in Travers' books.
Mary Martin, Bette Davis and Angela Lansbury were considered for the role of Mary Poppins. Casting directors saw Julie Andrews singing Camelot's "What do the Simple Folk Do" on the Ed Sullivan Show and immediately knew that they had to have her for Mary Poppins. They told Walt, who flew out to New York to see Julie sing her part on Broadway, and that was that. Andrews still had to pass muster with P.L. Travers, though, but it didn't end up being a problem - Travers adored her.
Travers wrote to Walt Disney to suggest Karen Dotrice for the role of Jane Banks, but Walt had already cast exactly that actress in the part. At least they agreed on one thing!
Julie Andrews almost didn't take the role - she was actually holding out for the Eliza Doolittle part in My Fair Lady that eventually went to Audrey Hepburn. Andrews had played the part on Broadway and loved it. Audrey may have played Eliza, but Julie Andrews was so brilliant in Poppins that she beat Audrey for both the Best Actress Golden Globe and Academy Award.
The actors who played Jane and Michael had already starred in a movie together - The Three Lives of Thomasina - and went on to do another one together post-Poppins: The Gnome-Mobile.
Matthew Garber was afraid of heights, so the crew paid him an extra dime every time he had to go up on the wires for the scenes where the kids are floating in the air. But they weren't always on wires - Disney didn't want people to look at the scene and go, "Oh, they clearly used wires for that," so sometimes wires were used, sometimes teeter totters were used, and sometimes they flipped the set on its side or upside down and filmed that way.
Next time you watch the movie, check out the queue of nannies lined up to interview for the nanny position - a bunch of them are actually men.
When the kids look surprised at all of the stuff Mary Poppins pulls out of her carpet bag, that was genuine shock. They couldn't see what was being fed to the bag from under the table, so when she pulled hat stands and huge potted plants out of that regular-sized bag, the kids were completely stunned.
Dick Van Dyke freely admits that his cockney accent was awful and in fact kind of gets a kick out of it.
Lots of the actors played multiple roles: Dick Van Dyke played Bert, of course, and also played Old Mr. Dawes the banker. Other than the title role, Julie Andrews also provided her own whistling accompaniment when Mary Poppins sings with the robin during "Spoonful of Sugar" and was also one of the Pearly ladies in "Supercalifragilisticexpialidocious." David Tomlinson, AKA Mr. Banks, was also the voice of Mary's umbrella when it talked and one of the jockeys in the animated horse race scene. In addition, he dubbed the voice for Admiral Boom's first mate.
A bunch of songs were deleted from the movie. A few include "The Chimpanzoo," which you can now hear on the 2004 special anniversary edition DVD; "Practically Perfect," which ended up being the music for "Sister Suffragette"; "Admiral Boom" which was to be Admiral Boom's theme song; and "Measure Up," which Mary Poppins was going to sing while measuring the kids with her magical tape measure. One song was actually repurposed for Bedknobs and Broomsticks and was called "The Beautiful Briny" in it.
A few tips from a Disneyphile: ask the Disneyland or Disneyworld Mary Poppins if she can say "supercalifragilisticexpialidocious" backward. She'll be able to do it, guaranteed. And check out the backroom of one of the shops in EPCOT's England: you'll find packages addressed to Mr. Banks at Cherry Tree Lane. One more: the train station in Frontierland at Disneyworld has various parcels and suitcases sitting around the station to make it appear more authentic. Look carefully and you'll see a wooden leg labeled "Smith," a little inside joke to Bert's bellybuster "I know a man with a wooden leg named Smith..."
Walt Disney himself came up with a lot of the gags during the scene where Admiral Boom fires his cannon and everything in the Banks house shakes. The part where Mrs. Brill catches the vase on her toe, the part where the piano rolls back into place itself, and how the whole crew just nonchalantly does this - all of those ideas stemmed from Walt.
When the kids and Mary clean up the trashed nursery, that was actually accomplished by filming a clean nursery, then knocking things over and throwing things about to make it look messy. Then they ran the film backward to show tables being uprighted all by themselves (and other things like that).
Elsa Lanchester, who played the childrens' former nanny Katie Nanna, was previously best-known for her role as the Bride of Frankenstein.
Mary Poppins' sets often ended up being used for other Disney productions. One episode of The Wonderful World of Color featured a haunted house, which was actually the Banks house covered with cobwebs and dust.
The Bird Woman is played by Jane Darwell, whom Walt Disney cast after remembering her amazing performance as Ma Joad in The Grapes of Wrath. He made sure she was given the full-out star treatment and was brought to the set in a limo and treated with great respect. It was to be her last film performance.
The "Chim-Chim Cheree" and"Step in Time" sequences are my favorites, I think. The background of the London rooftops is actually matte paintings done on glass. The "smoke" staircase was actually made out of sponge because it was assumed that if you were walking on smoke, it would have a bouncy feeling to it. The "Step in Time" dance had to be filmed twice because the film the first version was on got scratched. And I guess I'm not alone in loving the "Step in Time" scene - Walt enjoyed it so much he would come to watch the daily dance rehearsals and told the choreographers to go nuts and have fun with the steps.
Every member of the crew - not the cast, mind you, the crew - asked for a copy of the soundtrack.