Delillo was already a well-accomplished author some time before his '97 release, Underworld. Having already won many awards including a Pulitzer Prize and a Gugenheim fellowship, Delillo had already risen in the ranks garnering comparison to Thomas Pynchon and other late 20th century authors. Yet, during a time when people were wondering how he could write a more exquisite novel than Mao or White Noise, he released Underworld which immediately was regarded as his best work among literary critics.
The novel is a large work, over 800 pages with over a hundred characters, the complex Cold War story's success even surprised Delillo, who admitted in an interview that he didn't know whether the story would find an interested readership. The transcendent prose and other-worldly sense of the story makes the book one of the greatest accomplishments in Delillo's oeuvre, and one of the greatest of its kind.