Answer:
while writing the ‘Looking Glass’ story, Charles Dodgson (Lewis Carroll) used a lot of material that he had come up with earlier. In the article ‘Alice on the Stage‘ he remarked:
“[Through the] Looking Glass [was] made up almost wholly of bits and scraps, single ideas that came of themselves.”
He tied all those individual ideas together into a single story with the use of two main themes: chess and mirror images.
In the six years since he wrote Alice in Wonderland, Carroll had been teaching Alice and her sisters the game of chess. He made up stories to illustrate the moves of the pieces and the rules of the game. Many of these stories were used for his second ‘Alice’ story.
Step-by-step explanation: