Three major characteristics define Lewis's work: detail, satire, and realism. Lewis remarkably portrays ordinary life, ordinary characters, and ordinary speech. Many critics, including Heywood Broun, praised Lewis for his ability to meticulously reproduce different dialects and speech. Lewis used vivid detail to create scenes of the American middle class. His social satire was critical of American life and certain types of Americans and institutions which he felt harmed Americans and prevented the country from living up to its democratic ideals.
Lewis's novels fit under the umbrella of American social fiction, fiction whose primary purpose is to represent contemporary American society, primarily in a realist style with realistic language. Lewis artfully described American culture and life of the time, helping Americans see their own lives with their many flaws. Critics praised him, claiming that his writing represented the culture of the 1920s and 1930s. Mark Schorer, in his exhaustive biography, notes regarding Lewis's work, "American culture seems always to have had a literary spokesman, a single writer who presented American culture and American attitudes toward its culture, to the world" (270). Lewis was that author. The titles of two of his novels, Main Street and Babbitt, were introduced into the American vocabulary. These words developed their own cultural meanings.
In the wake of World War I, amidst the culture of the Jazz Age and the Great Depression, Lewis revealed to Americans their lives at a time when they were ready to listen. Lewis's representation of the middle class and its discontent was presented through satire and social criticism. Main Street is the epitome of the "Revolt from the Village" novel and the logical conclusion to a literary trend started by such writers as Edgar Lee Masters and Sherwood Anderson. Babbitt, Arrowsmith, and Elmer Gantry serve as critiques of different aspects of American society such as consumerism and conformity, the medical profession, and organized religion. It Can't Happen Here is a warning against the growth of fascism in our own country. Even a more minor text like The Man Who Knew Coolidge uses the distinctly American voice of the businessman, one that would be picked up by humorous writers like Robert Benchley and James Thurber.
Following his five major novels, Lewis's importance was secured when he became the first American to be awarded the Nobel Prize in 1930. Lewis also helped other young American authors. He was Elinor Wylie's first literary contact, and he encouraged her during the beginning of her career. Lewis assisted Frazier Hunt, writer for the Cosmopolitan, and helped him write Sycamore Bend. He encouraged Zona Gale, helped Edith Summers publish Weeds, called Harcourt on behalf of Pola Negri and asked them to publish her memoirs, and congratulated Thomas Wolfe on his first novel, Look Homeward, Angel. Later in his life, Lewis hired Barnaby Conrad as his personal assistant and helped him to write The Innocent Villa.
Some of his later novels were also bestsellers, includingCass Timberlane, a novel about the tension between husbands and wives in post war America, that was made into a film with Spencer Tracy and Lana Turner. Kingsblood Royal (1947), a novel about a man who discovers a black ancestor and endures attacks by his former friends and colleagues, exposed racism in middle class America to a white audience that had turned a blind eye to it.
Lewis influenced a number of authors in different ways. Authors who have written about businessmen in various guises, such as John Updike in the Rabbit series, draw on his thinking about the intersection between business and culture. Critics have also suggested that such authors as Philip Roth, J.F. Powers, T. S. Stribling, and Garrison Keillor drew on his social commentary.