Copyright status of The Wizard of Oz and related works in the United States
"The Wonderful Wizard of Oz" was published in 1900, and was the first to enter the public domain in "1956". This allowed Reilly & Lee, the publisher of all the other Oz books (as well as Baum's other books) to issue their own edition of "The Wizard of Oz", which had previously been published by George M. Hill Company and later by the Bobbs Merill Company after Hill went bankrupt..
Tin Woodman
The Tin Woodman, better known as either the Tin Man or (incorrectly) the Tin Woodsman (the third name appears only in adaptations, the first—and in rare instances, the second—was used by Baum), is a character in the fictional Land of Oz created by American author L. Frank Baum. Baum's Tin Woodman first appeared in his classic 1900 book "The Wonderful Wizard of Oz", and reappeared in many other subsequent Oz books in the series. In late 19th-century America, men made out of various tin pieces were used in advertising and political cartoons. Baum, who was editing a magazine on decorating shop windows when he wrote "The Wonderful Wizard of Oz", was reportedly inspired to invent the Tin Woodman by a figure he had built out of metal parts for a shop display.