From Making the List, by Michael Korda

From the chapter on the bestsellers of the 1940s:

Attentive fiction readers will also notice that while murder mysteries, historical novels, and romances inevitably take up a number of "slots" on the fiction list, most of the really big fiction bestsellers over the years are what publishers call "big novels," which is to say ambitious novels with a big theme, a big scope, larger-than-life-size characters, whether written at the "popular" level, like The Robe, or at the literary level, like For Whom the Bell Tolls. "Category" fiction certainly sells, but it is the big novel that publishers really look for, and—though perhaps not always consciously—readers, too. The Song of Bernadette, Kings Row, The Keys of the Kingdom, and Pearl S. Buck's Dragon Seed are all, in different ways, big novels, i.e., big in length, big in concept, with a big, central moral conflict, trying hard to be solid, serious, challenging, as well as entertaining. True, time, the ultimate judge of long-term bestsellerdom, has not been kind to them, nor even to Hemingway—Pearl S. Buck is seldom read today, Song of Bernadette hardly remembered, Kings Row and Keys of the Kingdom only by older readers—still, all of them were, as it were, considered "serious contenders" in their day.

The big novel could, of course, include romance; it might be "historical," but it first of all required a big subject, and a strong point of view about that subject. Very often it was sociological (Sinclair Lewis), or attempted to re-create and explain a whole alien culture (Pearl S. Buck on China, or, later, Norman Mailer on Egypt in Ancient Evenings), or sometimes it was a combination of ideology and reporting (For Whom the Bell Tolls, for example, but also, on a higher plane, War and Peace), but like a good French meal, it should leave the reader stuffed, satisfied, overwhelmed, in any event not hungry for more.

War, of course, was a major subject for such novels, though they tended to follow the war, not to get written during it, but whatever the subject, it was one of the two major categories of bestselling fiction, the big novel being trumped, as it were, only by that equally elusive phenomenon, "The Great American Novel," of which Moby-Dick is held to be the first example, except in the eyes of confirmed James Fennimore Cooper fans. The Great American Novel was best exemplified in the thirties by Thomas Wolfe—and in its contemporary form implied a big, long, multigenerational novel that at once illuminated and explained American life and was written by an American. It could not be "historical"; it had to have the kind of complex prose style that Theodore Dreiser, for example, always strived for; it had to be set firmly in the United States (which excluded most of the work of Hemingway and some of Fitzgerald's); and it had to make, or be thought by critics to have made, a serious, and perhaps even solemn, statement about American values.

Sinclair Lewis, Dreiser, Wolfe, and Steinbeck battled it out for supremacy in this area over the thirties and forties, though Dreiser seemed to many readers too heavy going, while Lewis was a bit of a hack (too many bestsellers written too quickly) and too many of Steinbeck's characters were quaint, fey, or out of the mainstream, which left Wolfe as the winner by default. In any case, these two categories—the big novel and the Great American Novel—tend to provide at least half of the fiction bestsellers and provide the all-important touchstone against which the importance and seriousness of a bestseller tends to be judged.
- pp. 81-83