http://www.biography.com/people/frank-baum-9202328#awesm=~oD7eJXXBS6aA9k

Literati Book Stall has a good copy of

L. Frank Baum: Creator of Oz: A Biography 

by Katharine M. Rogers

In this first full-length adult biography of Baum, Rogers discusses some of the aspects that made his work unique and has likely contributed to Oz’s long-lasting appeal, including Baum’s early support of feminism and how it was reflected in his characters, his interest in Theosophy and how it took form in his books, and the celebration in his stories of traditional American values. Grounding his imaginative creations, particularly in his fourteen Oz books, in the reality of his day, Katharine M. Rogers explores the fascinating life and influences of America’s greatest writer for children.