An interview with Ethan Mordden, whose The Guest List: How Manhattan Defined American Sophistication, from the Algonquin Round Table to Truman Capote’s Ball will be published by St. Martin’s.

The Guest List seems like a departure from your earlier writing—fiction, theater, the arts—where did this idea come from?

There's this story: W. S. Gilbert (of Gilbert and Sullivan) is in his study when a ceremonial Japanese sword falls from its wall mounting with a clatter. Gilbert: "I know! I'll write The Mikado!" In fact, ideas don't usually crash into consciousness that way. They just… slither in, and you say, "Oh. Right. Why didn't I think of that before?"

Your book spans the 1920s through the mid-‘60s; are there comparisons to be made—political, social, and/or cultural—with the decades following that period?

At the time of the Sacco and Vanzetti trial, in the 1920s, John Dos Passos wrote, "All right we are two nations," meaning Middletown versus the coastal Babylons. And we see it again in the tea party, which no one can describe because pundits want to categorize it as a political uprising when it is really the latest version of an almost mystically incoherent cultural revolution. Yes, it does have its political agenda, and some of its concerns are legitimate grievances about how Washington blows crazy dust into everything. Still, many of the tea party's utterances suggest the viewpoint of the blind, the worldview of the unworldly. One thinks of Groucho Marx singing, "Whatever it is, I'm against it." It's the Know Nothing Party of the mid-1800s. It's Prohibition. It's anger at occult doings in board rooms by men who communicate telepathically as they move money and declare wars. It's Middletown saying, "Someone is changing my life."

Regarding the subtitle—How Manhattan Defined American Sophistication, from the Algonquin Round Table to Truman Capote’s Ball—how did Manhattan define sophistication, and why?

"Sophistication" is a mixture, literally, and Manhattan's sophistication blended Irish, Jewish, Italian, black, and gay cultures into New York's unique ethnicity. It's not only smart; it's also tolerant. It's not only Dorothy Parker; it's also Ethel Waters. It's a curiosity about the world that only elitist art can satisfy. It's wit, imagination, the education of the many by the few. Cole Porter, for instance, widened the known universe with his sexual double meanings. When "Too Darn Hot," listing dating couples, includes "A marine" and "his queen," either you get it or you need a sophistication upgrade.

Your Guest List is crammed with people and events—how did you decide who and what “made the list,” and were there any people or events you needed to leave out for the sake of discretion?

In any compendium, I look for novelties, because they're more fun to write about and more fun for the reader. He wants surprise. I was fascinated by the war between Dorothy Thompson and Charles Lindbergh over American intervention in World War II. It was not only that he turned out to be a even-tempered but all the same fanatic Nazi, but that she was the most famous American woman after Mrs. Roosevelt, and now she's not even a has-been. She's utterly gone. And of course she married Sinclair Lewis and he wrote a novel about a Nazi takeover of America, and all of that is the very center of the book. It's the city woman against the narrow-cultured hayseed. And, no, I didn't leave anyone out for the sake of discretion. I don't have any discretion.

You end the book with Truman Capote’s November 1966 celebrity ball in the Plaza Hotel’s Grand Ballroom—why that particular event?

That was sophistication's last big night. The national culture was already moving to Los Angeles, away from New York and its music and lit and politics. Capote sums it all up as a one-man mixture: artist and gossip, achiever and failure, socialite and anti-socialite. After writing the biggest book since the Bible, In Cold Blood, Capote virtually dissolved as a talent. He blurred himself to death in the alcoholic's forever nap. And yet before that he was what New York sophistication was made of. He reminds us of the gala tragedienne's advice to the novice actress: when you exit, take everything with you, including the grand piano. Capote took it all with him.