The Secrets of 'Mad Men,' 10 Years in the Making

April 10, 2014 — -- Set in the glamorous, tumultuous backdrop of 1960s America, the AMC show "Mad Men" has captivated this decade of American viewers with the sinful, striving secrets of its principle characters.

But the secrets go beyond just what’s scripted and in an exclusive broadcast interview with ABC’s Diane Sawyer, the cast and creator of "Mad Men" opened the lid into their own box of surprises as the show embarks upon its final season.

Slideshow: Behind the scenes of "Mad Men" with creator Matthew Weiner.

The show’s protagonist is the glamorous ad man Don Draper, an embodiment of America in the 60s, a decade determined to sell itself.

"It's been one of the major themes of the show, like the outward image that's projected, and then what's behind it," said Jon Hamm, who plays Draper on the show.

Draper was raised in a house of shame – surrounded by prostitutes and suffering. To escape, he reinvents a new identity and a new life as an ad man at the Sterling Cooper and Partners agency. The show follows Draper’s journey through doubt, lies, alcohol and careless infidelity.

"He's damaged,” Hamm said. “He's damaged goods, in many ways, and he's doing the best he can."

The show’s creator, Matthew Weiner, confessed to Sawyer that where others may see a man to scorn, he loves Don.

“I don't judge. That’s been the secret of the whole show,” Weiner said. “I judge people in real life all the time, but I don't judge these characters. They're all trying really, really hard to be good people.”

It was more than 10 years ago that the show sprang from the Weiner's mind. He gave birth to the idea for "Mad Men" while still a writer on the HBO hit "The Sopranos." At first, no one wanted to touch it.

"For me, I wanted to write about why I was 35 years old and had so many good things in my life and was kind of unhappy still," Weiner told Sawyer. "And I wanted to sort of address that idea of … people who have a lot, saying 'Why do I feel this way?”

Even though the show is called "Mad Men," its heart, soul and sizzle comes from the women, who disclosed to Sawyer what they felt were the secret desires of their characters.

Christina Hendricks, who plays the sultry and tenacious office manager Joan, was originally planned to be a one-time bit character, but took on a role that has become central to the 1960s workplace. In today’s America, she would be running the company but for Joan, she feels forced to make the tortured decision to sleep with a client in order to get her shot at becoming partner.

"Our audience probably mentions Joan's strengths most of the time,” Hendricks said. “But I really enjoy playing her vulnerability, as well. I think that doesn’t get noticed…She gets hurt, and she goes home and deals with it.”

Draper's beautiful first wife, Betty, played by January Jones, is seen on-screen striving for perfection, but is imprisoned by the time.

"She's hopeful and not just a terrible mom. She's trying to be a good wife. She's trying to be a good mom. She's trying to just be happy and she doesn't succeed all the time," Jones said.

And then there's Peggy, pulled from the secretarial pool to become a copywriter and achieve unheard of success in advertising. Peggy seems to embody the type of career woman who battled against sexist thinking to achieve her goals, but Elisabeth Moss revealed that there is another side to her character that may come out more in the final season.

"She believes in love and I think she's optimistic about it,” said Moss. “She's, I think, a huge romantic and she wants to have that. I think she's lonely and doesn't want to be alone for the rest of her life, like all of us."

Among the secret tricks that were divulged to Sawyer at the interview, actor Vincent Kartheiser shaves back his hairline to better plays the anxious and ambitious Peter Campbell. His stubble revealed a thicker line of hair that the jealous character Pete would have coveted. But for all of Pete’s shortcoming, Kartheiser sees something noble in him.

"I hope [the audience] notice his loyalty and sometimes his bravery," Kartheiser said. "He makes, kind of, terrible decisions sometimes but sometimes they're the decisions that have to be made and he just steps up and says, 'I'll be the face of this kind of ugly truth.’”

And there is John Slattery, who plays Roger Sterling, the silver fox of the ad agency.

"I don't want the audience to expect that as soon as Roger walks in, he's gonna say something funny, smoke a cigarette, have a drink and leave,” Slattery said. "There's a generosity and a loyalty."

As the cast reflected on their decade of work, they said they’ve grown together as a kind of family. So close, in fact, that Hamm and Weiner actually appeared at the interview wearing the same red and navy striped socks.

“Hosiery is very important to the men in the show,” Hamm said with a laugh.

“I want to know what he’s thinking, so I'm like, what socks are you wearing today?” Weiner said.

But now as AMC's award-winning show is ready to end, there is a secret that not even the actors know.

"We've never really known more than one episode ahead, a couple of days before we do it," Moss said.

And though Weiner is still writing the last few episodes, he told Sawyer, that he already has the last sentence in his head. But for that, we’ll have to wait and watch.