Baum acknowledged the influence of the Brothers Grimm and Hans Christian Andersen, which he was deliberately revising in his "American fairy tales" to include the wonder without the horrors.
The Land of Oz and other locations
Local legend has it that Oz, also known as The Emerald City, was inspired by a prominent castle-like building in the community of Castle Park near Holland, Michigan, where Baum lived during the summer. The yellow brick road was derived from a road at that time paved by yellow bricks, located in Peekskill, New York, where Baum attended the Peekskill Military Academy. Baum scholars often refer to the 1893 Chicago World's Fair (the "White City") as an inspiration for the Emerald City. Other legends suggest that the inspiration came from the Hotel Del Coronado near San Diego, California. Baum was a frequent guest at the hotel and had written several of the Oz books there. In a 1903 interview with Publishers Weekly, Baum said that the name "OZ" came from his file cabinet labeled "O–Z".
Some critics have suggested that Baum may have been inspired by Australia, a relatively new country at the time of the book's original publication. Australia is often colloquially spelled or referred to as "Oz". Furthermore, in Ozma of Oz (1907), Dorothy gets back to Oz as the result of a storm at sea while she and Uncle Henry are traveling by ship to Australia. Like Australia, Oz is an island continent somewhere to the west of California with inhabited regions bordering on a great desert. One might imagine that Baum intended Oz to be Australia, or perhaps a magical land in the center of the great Australian desert.
Alice's Adventures in Wonderland
Another influence lay in Lewis Carroll's Alice's Adventures in Wonderland. A September 1900 review in the Grand Rapids Herald called The Wonderful Wizard of Oz a "veritable Alice in Wonderland brought up to the present day standard of juvenile literature". Baum found Carroll's plots incoherent, but he identified the books' source of popularity as Alice herself, a child with whom the child readers could identify; this influenced his choice of a protagonist. Baum was also influenced by Carroll's belief that children's books should have many pictures and be pleasurable to read. Carroll rejected the Victorian-era ideology that children's books should be saturated with morals, instead believing that children should be allowed to be children. Building on Carroll's style of numerous images accompanying the text, Baum combined the conventional features of a fairy tale (witches and wizards) with the well-known things in his readers' lives (scarecrows and cornfields).
American fantasy story
The Wonderful Wizard of Oz is considered the first American fairy tale because of its references to clear American locations such as Kansas and Omaha. Baum agreed with authors such as Carroll that fantasy literature was important for children, along with numerous illustrations, but he also wanted to create a story that had recognizable American elements in it, such as farming and industrialization.
Baum's personal life
Many of the characters, props, and ideas in the novel were drawn from Baum's experiences. As a child, Baum frequently had nightmares of a scarecrow pursuing him across a field. Moments before the scarecrow's "ragged hay fingers" nearly gripped his neck, it would fall apart before his eyes. Decades later, as an adult, Baum integrated his tormentor into the novel as the Scarecrow. According to his son Harry, the Tin Woodman was born from Baum's attraction to window displays. He wished to make something captivating for the window displays, so he used an eclectic assortment of scraps to craft a striking figure. From a washboiler he made a body, from bolted stovepipes he made arms and legs, and from the bottom of a saucepan he made a face. Baum then placed a funnel hat on the figure, which ultimately became the Tin Woodman. John D. Rockefeller was the nemesis of Baum's father, an oil baron who declined to purchase Standard Oil shares in exchange for selling his own oil refinery. Baum scholar Evan I. Schwartz posited that Rockefeller inspired one of the Wizard's numerous faces. In one scene in the novel, the Wizard is seen as a "tyrannical, hairless head". When Rockefeller was 54 years old, the medical condition alopecia caused him to lose every strand of hair on his head, making people fearful of speaking to him.
In the early 1880s, Baum's play Matches was being performed when a "flicker from a kerosene lantern sparked the rafters", causing the Baum opera house to be consumed by flames. Scholar Evan I. Schwartz suggested that this might have inspired the Scarecrow's severest terror: "There is only one thing in the world I am afraid of. A lighted match."
In 1890, Baum lived in Aberdeen, Dakota Territory, which was experiencing a drought, and he wrote a witty story in his "Our Landlady" column in Aberdeen's The Saturday Pioneer about a farmer who gave green goggles to his horses, causing them to believe that the wood chips that they were eating were pieces of grass. Similarly, the Wizard made the people in the Emerald City wear green goggles so that they would believe that their city was built from emeralds.
During Baum's short stay in Aberdeen, the dissemination of myths about the plentiful West continued. However, the West, instead of being a wonderland, turned into a wasteland because of a drought and a depression. In 1891, Baum moved his family from South Dakota to Chicago. At that time, Chicago was getting ready for the World's Columbian Exposition in 1893. Scholar Laura Barrett stated that Chicago was "considerably more akin to Oz than to Kansas". After discovering that the myths about the West's incalculable riches were baseless, Baum created "an extension of the American frontier in Oz". In many respects, Baum's creation is similar to the actual frontier save for the fact that the West was still undeveloped at the time. The Munchkins Dorothy encounters at the beginning of the novel represent farmers, as do the Winkies she later meets.
Baum's wife frequently visited her niece, Dorothy Louise Gage. The infant became gravely sick and died on November 11, 1898, from "congestion of the brain" at exactly five months. When the baby, whom Maud adored as the daughter she never had, died, she was devastated and needed to consume medicine. To assuage her distress, Frank made his protagonist of The Wonderful Wizard of Oz a female named Dorothy. Uncle Henry was modeled after Henry Gage, his wife Maud's father. Bossed around by his wife Matilda, Henry rarely dissented with her. He flourished in business, though, and his neighbors looked up to him. Likewise, Uncle Henry was a "passive but hard-working man" who "looked stern and solemn, and rarely spoke". The witches in the novel were influenced by witch-hunting research gathered by Baum's mother-in-law, Matilda. The stories of barbarous acts against accused witches scared Baum. Two key events in the novel involve wicked witches who both meet their death through metaphorical means.
Baum held different jobs, moved a lot, and was exposed to many people, so the inspiration for the story could have been taken from many different aspects of his life. In the introduction to the story, Baum writes that "it aspires to being a modernized fairy tale, in which the wonderment and joy are retained and the heart-aches and nightmares are left out." This is one of the explanations that he gives for the inspiration for The Wonderful Wizard of Oz. Baum, a former salesman of china, wrote in chapter 20 about china that had sprung to life.
Influence of Denslow
The original illustrator of the novel, W. W. Denslow, could also have influenced the story and the way it has been interpreted. Baum and Denslow had a close working relationship and worked together to create the presentation of the story through the images and the text. Color is an important element of the story and is present throughout the images, with each chapter having a different color representation. Denslow also added characteristics to his drawings that Baum never described. For example, Denslow drew a house and the gates of the Emerald City with faces on them. In the later Oz books, John R. Neill, who illustrated all of the sequels, continued to include these faces on gates.
Allusions to 19th-century America
Baum did not offer any conclusive proof that he intended his novel to be a political allegory. Historian Ranjit S. Dighe wrote that for 60 years after the book's publication, "virtually nobody" had such an interpretation until Henry Littlefield, a high-school teacher. In his 1964 American Quarterly article, "The Wizard of Oz: Parable on Populism", Littlefield posited that the book contained an allegory of the late 19th-century bimetallism debate regarding monetary policy.
Littlefield's thesis achieved some support, but has been strenuously attacked by others.