Gary Krist is the author, most recently, of “Empire of Sin” and “City of Scoundrels.”

Being one of the premier literary figures of your generation can be a lonely business. Just ask Ernest Hemingway. According to Hadley Richardson, the author’s first wife, Hemingway always had trouble finding friends he could connect with “on his level, and with the same interests.” But there was one notable exception: “John Dos Passos,” she once told an interviewer, “was one of the few people . . . whom Ernest could really talk to.”

Certainly the two writers had a few significant things in common. Both born in Chicago, they each served a formative stint as an ambulance driver in Europe during World War I, distilling the experience into war novels that helped shape the postwar American consciousness. And for several decades around the mid-1900s, both would have appeared on virtually any critic’s list of the greatest American novelists of the century.

The writer John Dos Passos, an intimate friends of Ernest Hemingway’s (Houghton Mifflin Company/Associated Press)

But there the similarities ended. Dos Passos, who was born out of wedlock, grew up in a series of European hotel rooms and was educated at Choate and Harvard. Sickly and physically awkward, he wore thick eyeglasses, spoke with a stutter and was never much of a ladies’ man. Hemingway, the product of a much more stable and conventional Midwestern family, never went to college but always exuded an intellectual confidence and insouciant athleticism that made him a great favorite with the opposite sex. Dos Passos was a lifelong political activist, while Hemingway (with one or two exceptions) typically steered clear of movements and causes. Books by Dos Passos seldom sold well; books by Hemingway seldom didn’t. And yet, as James McGrath Morris illustrates in his trim and absorbing new book, somehow the two writers managed to maintain an intense, often competitive friendship over many years — until one major disagreement in the 1930s tore them apart, leaving behind a bitterness that lasted until Hemingway’s suicide in 1961.

It was Dos Passos, the elder of the pair by three years, who was first out of the gate in the race to literary prominence. Although his first novel fizzled in obscurity, his second — “Three Soldiers,” published in 1921 and based on his harrowing experiences during the Great War — was a controversial but commercial success. Many critics condemned the book for its overwhelmingly nihilistic view of the conflict (a writer in the New York Times called it “arrant tommyrot”), but most agreed that it was brilliantly written and gave it the kind of extensive coverage reserved for major publishing events.

By the time Dos Passos and Hemingway became friends in Paris in 1923 (they had met briefly in June 1918 while driving ambulances in Italy), a somewhat envious Hemingway had not yet made much of an impression on the literary world. Even so, he clearly regarded the older writer as a peer rather than a mentor. The two would sit for hours in their favorite cafe (La Closerie des Lilas in Montparnasse), drinking vermouth with cassis and reading to each other from the King James Bible. Dos Passos did what he could to get his friend’s work noticed, using his contacts to help Hemingway break into the New York publishing world. But ultimately Hemingway didn’t need the assistance. His first major novel, “The Sun Also Rises,” proved to be an international sensation when it appeared in 1926, catapulting its author directly into the upper echelon of American writers.

Ernest Hemingway stands on the Bridge of Sighs in Venice. (A.E. Hotchner/Library of Congress via AP)

Equals at last, the two writers met frequently over the next years, vacationing together in places like Key West and various Alpine ski resorts. They had many friends in common; Dos Passos even married Hemingway’s old high school crush, Katy Smith. And although their prose styles differed drastically, each sought out the other’s editorial advice, the spartan minimalist and the cinematic maximalist somehow finding common critical ground. But while each writer published his share of winners and losers over the years, a consistent pattern soon emerged in their reviews and royalty statements — “Hemingway had fame and fortune,” as Morris puts it. “Dos Passos had unremunerated literary praise.”

The resulting imbalances put some pressure on their relationship. (Hemingway found himself in the annoying situation of having to lend money to a rival who’d made the cover of Time magazine before he did.) But the friendship endured through the late ’20s and early ’30s. During these years, Dos Passos tried to involve his friend in some of the left-wing political campaigns he championed (e.g., the Sacco and Vanzetti defense), though without much success. But the start of the Spanish Civil War in 1936 changed all of that. Hemingway, who seemed to find a bloody war as invigorating as a bloody bullfight, embraced the anti-fascist cause with gusto — just at a time when Dos Passos was becoming disenchanted with communism and with leftist politics generally. The two ended up going to Spain to collaborate on a documentary, but an incident in which a Soviet special brigade executed a friend of Dos Passos (on dubious evidence of spying) led to a decisive blowout. Dos Passos believed that the injustice had to be exposed in the press; Hemingway felt that doing so would be a betrayal of the anti-fascist cause in the war. They parted as enemies on a Parisian train platform in May 1937. In a subsequent letter to Dos Passos, Hemingway insisted that he no longer wanted to have anything to do with his former friend.

Whether the story of this turbulent literary friendship will matter to casual readers is a debatable question. Posterity, after all, has not been kind to Dos Passos. While not exactly a footnote in American letters, he is no longer widely read beyond the university classroom, while Hemingway is still, well, Hemingway. But Dos Passos’s best work bristles with verbal energy, and it achieves a philosophical scope that Hemingway rarely matched. Here’s hoping that Morris’s book can help to even up the score of their posthumous literary reputations.

The Ambulance Drivers
Hemingway, Dos Passos, and a Friendship Made and Lost in War

By James McGrath Morris

Da Capo. 312 pp. $27