In 1941 Bellow became a naturalized US citizen, after discovering upon attempting to enlist in the armed forces that he had immigrated to the United States illegally as a child. In 1943, Maxim Lieber was his literary agent.

From 1946 through 1948 Bellow taught at the University of Minnesota. In the fall of 1947, following a tour to promote his novel The Victim, he moved into a large old house at 58 Orlin Street SE in the Prospect Park neighborhood of Minneapolis.

In 1948, Bellow was awarded a Guggenheim Fellowship that allowed him to move to Paris, where he began writing The Adventures of Augie March (1953). Critics have remarked on the resemblance between Bellow’s picaresque novel and the great 17th Century Spanish classic Don Quixote. The book starts with one of American literature’s most famous opening paragraphs, and it follows its titular character through a series of careers and encounters, as he lives by his wits and his resolve. Written in a colloquial yet philosophical style, The Adventures of Augie March established Bellow’s reputation as a major author.

In 1958, Bellow once again taught at the University of Minnesota. During this time, he and his wife Sasha received psychoanalysis from University of Minnesota Psychology Professor Paul Meehl.

When Bellow was nine, his family moved to the Humboldt Park neighborhood on the West Side of Chicago, the city that formed the backdrop of many of his novels. Bellow’s father, Abraham, had become an onion importer. He also worked in a bakery, as a coal delivery man, and as a bootlegger. Bellow’s mother, Liza, died when he was 17. She had been deeply religious and wanted her youngest son, Saul, to become a rabbi or a concert violinist. But he rebelled against what he later called the “suffocating orthodoxy” of his religious upbringing, and he began writing at a young age. Bellow’s lifelong love for the Bible began at four when he learned Hebrew. Bellow also grew up reading Shakespeare and the great Russian novelists of the 19th century. In Chicago, he took part in anthroposophical studies at the Anthroposophical Society of Chicago. Bellow attended Tuley High School on Chicago’s west side where he befriended fellow writer Isaac Rosenfeld. In his 1959 novel Henderson the Rain King, Bellow modeled the character King Dahfu on Rosenfeld.

Bellow lived in New York City for a number of years, but he returned to Chicago in 1962 as a professor at the Committee on Social Thought at the University of Chicago. The committee’s goal was to have professors work closely with talented graduate students on a multi-disciplinary approach to learning. Bellow taught on the committee for more than 30 years, alongside his close friend, the philosopher Allan Bloom.

Bellow hit the bestseller list in 1964 with his novel Herzog. Bellow was surprised at the commercial success of this cerebral novel about a middle-aged and troubled college professor who writes letters to friends, scholars and the dead, but never sends them. Bellow returned to his exploration of mental instability, and its relationship to genius, in his 1975 novel Humboldt’s Gift. Bellow used his late friend and rival, the brilliant but self-destructive poet Delmore Schwartz, as his model for the novel’s title character, Von Humboldt Fleisher. Bellow also used Rudolf Steiner’s spiritual science, anthroposophy, as a theme in the book, having attended a study group in Chicago. He was elected a Fellow of the American Academy of Arts and Sciences in 1969.

Propelled by the success of Humboldt’s Gift, Bellow won the Nobel Prize in literature in 1976. In the 70-minute address he gave to an audience in Stockholm, Sweden, Bellow called on writers to be beacons for civilization and awaken it from intellectual torpor.

From December 1981 to March 1982, Bellow was the Visiting Lansdowne Scholar at the University of Victoria (B.C.), and also held the title Writer-in-Residence.

There were also other reasons for Bellow’s return to Chicago, where he moved into the Hyde Park neighborhood with his third wife, Susan Glassman. Bellow found Chicago vulgar but vital, and more representative of America than New York. He was able to stay in contact with old high school friends and a broad cross-section of society. In a 1982 profile, Bellow’s neighborhood was described as a high-crime area in the city’s center, and Bellow maintained he had to live in such a place as a writer and “stick to his guns.”

While sales of Bellow’s first few novels were modest, that turned around with Herzog. Bellow continued teaching well into his old age, enjoying its human interaction and exchange of ideas. He taught at Yale University, University of Minnesota, New York University, Princeton University, University of Puerto Rico, University of Chicago, Bard College and Boston University, where he co-taught a class with James Wood (‘modestly absenting himself’ when it was time to discuss Seize the Day). In order to take up his appointment at Boston, Bellow moved in 1993 from Chicago to Brookline, Massachusetts, where he died on 5 April 2005, at age 89. He is buried at the Jewish cemetery Shir HeHarim of Brattleboro, Vermont.

Bellow is represented in the collection of the National Portrait Gallery with six portraits, including a photograph by Irving Penn, a painting by Sarah Yuster, a bust by Sara Miller, and drawings by Edward Sorel and Arthur Herschel Lidov. A copy of the Miller bust was installed at the Harold Washington Library Center in 1993. Bellow’s papers are held at the library of the University of Chicago.

Despite his identification with Chicago, he kept aloof from some of that city’s more conventional writers. In a 2006 interview with Stop Smiling magazine, Studs Terkel said of Bellow: “I didn’t know him too well. We disagreed on a number of things politically. In the protests in the beginning of Norman Mailer’s Armies of the Night, when Mailer, Robert Lowell and Paul Goodman were marching to protest the Vietnam War, Bellow was invited to a sort of counter-gathering. He said, ‘Of course I’ll attend’. But he made a big thing of it. Instead of just saying OK, he was proud of it. So I wrote him a letter and he didn’t like it. He wrote me a letter back. He called me a Stalinist. But otherwise, we were friendly. He was a brilliant writer, of course. I love Seize the Day.”

Bellow was married five times, with all but his last marriage ending in divorce. His son by his first marriage, Greg Bellow, became a psychotherapist; Greg Bellow published Saul Bellow’s Heart: A Son’s Memoir in 2013, nearly a decade after his father’s death. Bellow’s son by his second marriage, Adam, published a nonfiction book In Praise of Nepotism in 2003. Bellow’s wives were Anita Goshkin, Alexandra (Sondra) Tsachacbasov, Susan Glassman, Alexandra Ionescu Tulcea, and Janis Freedman. In 2000, when he was 84, Bellow had his fourth child and first daughter, with Freedman.