WHEN L. FRANK BAUM began writing his tales of Oz at the end of the 19th century, he could not have foreseen their endurance in popular culture well into the 21st. In addition to The Wizard of Oz and Wicked on screen and on stage, Baum’s characters have been re-imagined into many literary works, including those of an obscure author and publisher named Marsh “March” Laumer.