That probably explains why I never get information about its box office records. Also, whenever I research the Disney films, I see Robin Hood then The Rescuers, but then I wonder "What about The Many Adventures of Winnie the Pooh?"
I consider them to be released seperately as featurettes first by chronological order because it was always Walt Disney's intention to create a feature film, but he decided to make shorts instead — after production had begun — to familiarize US audiences with the characters. It's just like Kathryn Beaumont getting the role of Alice in Alice in Wonderland because Disney was looking for an Alice "that would be English enough to satisfy British audiences and preserve the feeling of an English literary classic, but not so English that it would put off American audiences." It's sort of like letting the American audiences become well-acquainted with the semi-English characters in a nearly-American animated movie.