Heather Halpin Perez is a mild-mannered archivist by day, toiling away in the Atlantic City Free Public Library’s dry, dusty local history section, the Alfred M. Heston Collection.

She has a much more glamorous title, however, on Sunday nights, one that stems from an ongoing hookup with Hollywood — specifically with a glitzy, award-winning, darling-of-the-critics TV show. Perez is nationally known as “Boardwalk Empire’s Librarian.”

At least that’s how the 34-year-old mother of two young daughters was identified in a profile by American Libraries magazine, a professional journal not normally known for its sensational headlines.

Perez, of Absecon, emphasizes that she’s not on the staff of the HBO hit, which opens its third season today at 9 p.m. She also wants to make it clear that she’s not on the payroll — although her family and friends do like seeing her name in the credits and sometimes tease her about it. She usually shows up as a “historical consultant” when the names roll by in small print at the end of each episode.

Ed McGinty, an Atlantic City native and the lead historical researcher on the “Boardwalk Empire” staff, appreciates that when he calls her for help, Perez appreciates that even his most arcane questions can have an urgency to them.

“The archive is an incredible resource, and Heather is just so knowledgeable about what’s in there,” said McGinty, a “1980s” graduate of Holy Spirit High School who grew up mostly in Absecon, but now lives in Brooklyn, N.Y. “Whenever I need some specifics, say a photograph ... anything I can’t find anywhere else, I call her.”

He has asked her to find Atlantic City’s American Legion hall number in the 1920s, and “who was on the political ticket in the election of 1920,” McGinty recalled from years of dealing with the archivist — including several straight days he spent in the Heston Collection shortly after he was hired for the then-planned show. “She was able to provide the entire ticket.”

McGinty, who also has a small acting part as “Boss Boyd” on the show, acknowledges that the writers could get by without such details.

“But if it’s out there and you can find it ... Terry Winter wants to get as specific as he can,” he said, referring to the show’s creator. “So if the information is available, why not use it?”

And when McGinty calls, because of the show’s production schedule, “I kind of need to have the question answered pretty quickly. Heather gets to it as soon as possible.”

Perez added that while she enjoys her relationship with the show, she doesn’t do anything for “Boardwalk Empire” that she wouldn’t do for anyone else who calls or visits the library with questions on Atlantic City’s past.

“We help business people all the time. ... We help people who call about the picture of the hotel where their grandmother stayed on her honeymoon,” she said. “We help Press reporters, NBC News,” and her list goes on.

Allen “Boo” Pergament, who grew up in Atlantic City and keeps an extensive museum of its history in his Margate home, also speaks highly of the keeper of the library’s archives.

“First of all, Heather is an extremely intelligent, capable and skillful individual,” said Pergament, 80. “And she has become one of the most knowledgeable people about Atlantic City, even though she wasn’t from here. Most people who deal with (local history) were either born and raised here or have been into it for a long time. ... But she has a knack or a skill for learning these things.”

Perez, a native of Lynchburg, Va., said she had never even set foot in New Jersey before she came across an online ad in 2006 saying that Atlantic City’s library was looking to hire an archivist. At the time, she was a graduate student in the library program at the University of Maryland — with an undergraduate degree from the College of William & Mary and an internship at the Smithsonian Institution — looking for a job as a research librarian.

She read “The Last Good Time,” by Jonathan Van Meter — which focused on Atlantic City through the prism of the legendary 500 Club and the nightclub’s owner, Skinny D’Amato — as a crash course to prepare for her interview. And she got the job.

That was six years ago. Author Nelson Johnson’s scholarly history of the city, “Boardwalk Empire: The Birth, High Times, and Corruption of Atlantic City,” had been published four years earlier. But turning the book into an HBO series wasn’t even in the rumor stages yet, at least not in public.

Since the TV show debuted in 2010 and took off, there has been increased interest in Atlantic City history — even if most historians agree that the fictionalized show is much better as a piece of entertainment than as a precise look at the city’s past.

Perez said that although her name shows up on “Boardwalk Empire,” she doesn’t watch every episode. But she does make it a point to check the plot summary each week, as a heads-up on what questions she can expect to get from viewers made curious by something they spotted on the show.

The library gets inquiries from as far away as Finland — as evidenced by the newspaper copy the Heston Collection now has, in Finnish, with a picture of Nucky Johnson, the old Atlantic City political boss and the basis for the show’s main character, played by Steve Buscemi. That portrait came from the Heston archives, of course.

“It’s such a great time to be interested in Atlantic City history, and showcasing Atlantic City history,” Perez said, adding that the library has plans to expand the space for its historic collection. Plus the library has taken over the Atlantic City Historical Museum, which recently reopened on Garden Pier after being closed for most of a year. That move expanded Perez’s duties — she now oversees the museum, too.

She’s excited about having more space to show off the contents of the cramped Heston room, and excited to note that Garden Pier is about to celebrate a historic milestone of its own, its 100th anniversary, next year.

While she said she’s far from an expert on Atlantic City history, “When I’m answering questions for other people, I certainly am trying to learn as much as I can.” And she’s blessed with a memory that helps “dates and names stick in my mind. So that can help me come up with answers pretty quickly.”

Perez is happy to credit the TV show with helping expand interest in Atlantic City’s history. But for all its popularity and influence, she knows “Boardwalk Empire” didn’t create the city’s story. It just built on the truth.

“Everyone was in Atlantic City, of course,” she said, running through a list of presidents from memory, “Hoover, Taft ... Johnson;” world-changing inventors, “Edison;” and heavyweight champs, “Jack Dempsey. ... I mean, Atlantic City was the place to be.”

Contact Martin DeAngelis:

609-272-7237