Answer:
i think i'm not sure The history of Oz prior to The Wonderful Wizard of Oz (often called the prehistory of Oz as it takes place before Baum's "histories") is often the subject of dispute, as Baum himself gave conflicting accounts. In The Wonderful Wizard of Oz, the title character recounts that he was a ventriloquist and a circus balloonist from Omaha, and during one flight the rope for his parachute vent became tangled, preventing him from descending until the next morning, and he awoke to find that he was floating over a strange land. When he landed, the people thought he was a great wizard because of his ability to fly. He did not disabuse them of this notion, and with his new power over them, he had them build a city with a palace in the center of Oz. He also ordered them to wear green glasses so it would appear to be made entirely of emeralds