Final answer:
The novel 'Babbitt' by Sinclair Lewis satirizes the conformity of the American middle class, critiquing societal norms and materialism through the character George F. Babbitt.
Step-by-step explanation:
The novel that satirized the conformity of the American middle class during its era is D. Babbitt by Sinclair Lewis. This novel is a social satire that critiques the pressures to conform to societal norms and the materialism of the American middle class during the 1920s. The protagonist, George F. Babbitt, is a successful real estate agent who becomes disillusioned with his conformist lifestyle and seeks deeper meaning in life beyond the acquisition of wealth and status, which highlights the author's critique of American society at the time.