“The past is a foreign country; they do things differently there,” L.P. Hartley wrote in the classic novel (and later film), “The Go-Between.”

It’s a sentiment that neatly sums up a question posed by this summer’s most chewed-over television series, AMC’s “Mad Men”: How do you recapture the past? The show takes us back to the New York advertising world of 1960, a time within living memory for some, and as alien as Imperial Rome (perhaps more so in some ways) for others.

Getting the clothes and décor right is the easy part. Behavior is trickier. Does “Mad Men” accurately evoke the mood of 1960, or is it, as some have suggested, closer in spirit to 1955? Did people really speak that way back then? Were women quite so docile and men so free with the belittling sex talk? Did everyone drink and smoke that much?

It’s surprisingly hard to be sure. Hartley’s protagonist, an old man recollecting a childhood summer, was thinking about his own past, not someone else’s, when he wrote that it was “a foreign country.” That gives you a sense of what Matthew Weiner, the creator of “Mad Men,” is up against.

The standard referents for the 1950s and early ’60s are writers like John Cheever and Norman Mailer, along with films such as “The Apartment” and “Sweet Smell of Success.” I’d add to that list the New York poet Frank O’Hara, a curator at the Museum of Modern Art who, though he never worked in advertising, was surely the first person to write poems studded with product placements.

With its journalistic precision, down to exact dates and even train times, O’Hara’s poetry is an invaluable guide to the period. He may have been part of a gay, bohemian downtown scene that Mr. Weiner’s “Mad Men” would hardly have known about, but on weekdays he inhabited the identical Midtown geography. In one of his most famous poems, “The Day Lady Died,” there’s a stanza that corroborates the show’s booze- and tobacco-soaked ambience.

Describing a little shopping trip before he heads for a weekend in East Hampton on July 17, 1959, O’Hara wrote:

“And for Mike I just stroll into the PARK LANE / Liquor Store and ask for a bottle of Strega and / then I go back where I came from to 6th Avenue / and the tobacconist in the Ziegfield Theatre and / casually ask for a carton of Gauloises and a carton / of Picayunes ….”

Not packs, but cartons. Yet even where “Mad Men” would appear to be on safe ground — yup, people did a lot of drinking and smoking — there remain subtler questions, such as how exactly people smoke, or how they did back then (and whether contemporary actors still know how to look natural doing it). During a live-blogging session on “Mad Men” hosted by Tom Watson, editor of NewCritics.com, one commenter said, “There is something phony about the way theactorsaresmokingontheshow and I can’t put my finger on it.” Someone else added: “They’re not inhaling.”

The real critical canon fire, however, was supplied by a poster called “Tristan.” “People, people,” he wrote, rallying the troops. “You can’t really think that people in 1960 were really like this! These are mirages, twists of smoke! The ad men of that time were lethal motherf—–s, really smart, profane, and funny, with Ivy League degrees on their resumes. And the women were not zombies who stood around overdressed smoking with their dish washing gloves on. In fact no one in this show seems to know how to smoke. And people of this class did not hit children who were not their own. I never, ever saw it happen.”

Worst of all, according to this poster, the show completely fails to summon up the energy of the period. It may have been drinksodden, but it wasn’t depressed and exhausted. “This was a time of urgency, when modernism was feverish and drove everything in the city and the postwar suburbs seemed to be as much a part of that future as Madison Avenue. This show is a shadow play on a wall, completely without dimension.”

The characterization of the period as “feverish” reminded me of another famous O’Hara poem, about the day Nikita Khrushchev visited the United Nations. It begins: “Khrushchev is coming on the right day! / the cool graced light / is pushed off the enormous glass piers by hard wind / and everything is tossing, hurrying on up / this country / has everything but politesse, a Puerto Rican cab driver says / and five different girls I see / look like Piedie Gimbel….”

That was written in the fall of 1960, and suggests that for O’Hara, at least, this was indeed an urgent, feverish time: everything is tossing, hurrying on up.

And what about that cabbie? If there were a scene in “Mad Men” in which the hero, Don Draper, got into a taxi driven by a Puerto Rican who said “this country has everything but politesse,” would the Internet discussion boards light up with mockery? One can imagine the questions: Did Puerto Ricans even drive cabs back then? Would a cab driver use the word “politesse”? Surely a member of an ethnic minority — cue heavy-breathing moral self-righteousness — would think a lack of European-style formality was the least of America’s problems in 1960.

Responding to a review of the show in Entertainment Weekly, a poster named Penny was much more positive. “I remember life in 1960 and this show pretty much nailed it. One of the comments here was about how offensive it was, and too much sexual harassment, and not enough lines assigned to people of color. Hate to tell you this, but that’s how it was.”

For the record, I’m still enjoying “Mad Men,” despite its sultry tempo, meandering plot, and increasingly grouchy hero. But perhaps that’s the point. Draper may seem like a hot shot, but he’s close to being over the hill. In 1960, O’Hara himself had only a couple of productive years left. By the time of his death in 1965, at age 40, his mood had turned sour and his muse unreachable. Much the same could be said of Draper. If Mr. Weiner’s take on the period seems somber, it’s at least partly because his hero is not a happy man. What the past is like depends a lot on whose past you’re talking about.

bbernhard@nysun.com