Final answer:
The novel that satirized the conformity of the American middle class is 'Babbitt' by Sinclair Lewis.
Step-by-step explanation:
The novel that satirized the conformity of the American middle class is Babbitt by Sinclair Lewis. Published in 1922, Babbitt is a critique of the materialistic and conformist values of the 1920s middle-class society in the United States. It follows the life of George F. Babbitt, a successful real estate agent who becomes disillusioned with his own superficiality and the empty pursuit of wealth and success.