Answer: It had a huge impact on the setting of TKAM.
Explanation: The Great Depression has a lot to do with To Kill a Mockingbird. The catalyst for the Great Depression was the Wall Street "crash" (when stock prices dropped sharply). The Great Depression was making everyone poor, but luckily the major protagonists were well-off to a certain extent. Many characters in the novel are extremely poor, such as the Ewells and the Cunninghams, so 'The Great Depression' helps Harper Lee show and differentiate between different classes of Maycomb and how economically diverse it is.