What authors influenced Baum?
This is a hard question to answer, primarily because nobody can say for sure. Baum was a fan of Charles Dickens, however, and so was probably influenced by him. Lewis Carroll, of course, was a major influence, as his Alice books were so new and popular, and have many similarities to the Oz books. Nathaniel Hawthorn also seems to have influenced Baum, as his story “Feathertop,” popular in the 19th century, seems to be the inspiration for the Scarecrow, Jack Pumpkinhead, or both characters. (Several websites now carry “Feathertop,” so you can read it for yourself at http://www.eldritchpress.org/nh/ft.html or http://www.online-literature.com/hawthorne/135/ or http://www.classicreader.com/read.php/sid.6/bookid.284/, among other sites.) Baum spoke highly of other writers in newspaper interviews, but in many cases, the editions of their works in his library had never been read.