Baum, L. Frank: - nLyman Frank Baum (1856-1919) was a beloved American author known for his childrens books. Most notably, Baum authored The Wonderful Wizard of Oz. He went on to write fourteen titles in the Oz series along with forty-one additional novels and an enormous collection of other works including over 200 poems. The Wonderful Wizard of Oz was eventually adapted into a screenplay in 1939 and became one of the cornerstones of American film. It has been widely regarded as one of the greatest films in cinema history.n