The following is from Ben Yagoda's About Town: The New Yorker and the World It Made.
The final piece of this particular puzzle was James Grover Thurber, a native of Columbus, Ohio, who, in June 1926, was deposited in New York after a year's sojourn in Paris. He had some experience as a newspaperman, but his aspirations were literary and comical, and he began peppering the New Yorker with submissions. After being rejected twenty times in a row, Thurber was seriously considering returning to Ohio, deciding to stay only when FPA [Franklin Pierce Adams] devoted an entire "Conning Tower" to one of his New Yorker rejects. Soon after that he took a reporter's job at the New York Evening Post, and soon after that the New Yorker finally bought something he had written. The circumstances of that first acceptance are telling. The writer Joel Sayre, a close friend from Columbus, told Harrison Kinney, "I was lounging on a sofa in the Thurbers' apartment one Sunday afternoon in January 1927. Thurber had been working away at his typewriter on something he hoped to sell to the New Yorker. Althea [Thurber's wife] said to him, 'Aren't you spoiling your stories by spending too much time on them?' She suggested, half in fun, that he set an old alarm clock to ring in forty-five minutes and try to finish his article within that time. Thurber did. Then he retyped it cleanly and sent it off to the New Yorker. He received a check for forty dollars."
The rejected pieces are lost to history, but Sayre's anecdote suggests that their problem lay in their being labored, obvious -- not casual. The accepted one, titled "An American Romance," was so brief and offhand that few people reading the issue of March 5, 1927, probably even remembered it into the next day. But in the light of literary history it has an air of absolute inevitability. The piece begins:
"The little man in an overcoat that fitted him badly at the shoulders had had a distressing scene with his wife. He had left home with a look of serious determination and had now been going around and around in the central revolving door of a prominent department store's main entrance for fifteen minutes."
The little man continues to go around for two hours more, attracting, in turn, a crowd of onlookers, a pack of newspaper reporters, and an assortment of offers from motion picture companies. The whole ridiculous tableau mildly satirized the odd 1920s trend of English Channel-swimming, flag-pole-sitting, and the like. But the theme is immaterial. The astonishing thing about the piece is the way that first paragraph points the way to James Thurber's contribution to the New Yorker and to American literature. "The little man" -- ineffectual and quietly resentful in the face of the forces ruling his life -- would become the best-known creation of Thurber and, by extension, the New Yorker, culminating in the 1939 "The Secret Life of Walter Mitty." The throwaway reference to a "distressing scene with his wife" retrospectively sounds the starting pistol for Thurber's exhaustive, merciless, and meticulous three-decade chronicle of the war between men and women, especially between husbands and wives.