First off, the fact that it is a collection of stories that have nothing to do with each other makes it unusual. The Magical Monarch of Mo, while technically a bunch of short stories, is more of an episodic novel while Little Wizard Stories of Oz are all Oz stories.
Second of all, the scope of each story is much smaller. Baum doesn't create any fantastic lands or vast adventures. The stories are more like quirky little incidences. With the Wizard of Oz, Baum said 'Look at this amazing world!' With American Fairy Tales, it's more of 'Hey, look what I found in the cupboard.'
Third, the tone is more snide and sarcastic, as opposed to whimsical and wondrous. Some of the morals are downright subversive. American Fairy Tales borders on being deconstructions of children's stories.
When I learned that the stories were originally serialized in newspapers, things fell into place. Of course, the stories would be more stand alone and more aimed at an older audience under those circumstances.
And compared to the other newspaper serial I read by Baum, the Queer Visitors from the Marvelous Land of Oz, American Fairy Tales is a lot more enjoyable and better written. I found the Queer Visitors a dreadful read but I enjoyed American Fairy Tales all right.
The truth is, American Fairy Tales is one of Baum's weaker pieces. Which doesn't mean that it's bad. The man wrote some really good children's books.
However, it is actually pretty low on the list of his books that I'm planning on reading to my son. It's just a little too sarcastic, not enough whimsy. It really seems to be more suited for an adult audience that wants to laugh at the structure of children stories.
And there is absolutely nothing wrong with that. Deconstructing fairytales can be great. However, Baum is not the guy who I reach for when I am looking for that.