It’s hard to remember now, but back in 2007, AMC was the channel where your grandpa watched black-and-white westerns. It wasn't a "prestige" destination. Then came a script about 1960s ad men that had been floating around Hollywood for years. When we talk about the Mad Men: Season 1 cast, we’re basically talking about a group of "who’s that?" actors who turned into icons almost overnight. Honestly, the chemistry in that first season shouldn't have worked. You had a lead who was a soap opera veteran, a child actor trying to go legit, and a bunch of Broadway performers shoved into a tiny basement set in New York.
Matthew Weiner, the creator, famously fought for these people. He didn't want big stars. Big stars bring baggage. He wanted faces that looked like they belonged on a 1960s postcard—sharp, structured, and maybe a little bit hollow behind the eyes.
The Mystery of Jon Hamm and the Sterling Cooper Office
Jon Hamm was not the first choice for Don Draper. He wasn't even the tenth. He has told stories about being at the bottom of the list, literally "number one hundred" according to some casting notes. Before he became the face of the Mad Men: Season 1 cast, Hamm was a guy who couldn't get a break, often losing roles to people who looked "friendlier." But Draper isn't friendly. He's a shark in a gray flannel suit.
In that first season, Hamm had to carry the entire weight of a man living a double life. You see it in the pilot, "Smoke Gets in Your Eyes." He isn't just playing an ad man; he's playing a man playing an ad man. It’s meta.
Beside him sat John Slattery as Roger Sterling. Originally, Slattery wanted to play Don. Can you imagine? It would have been a disaster. Slattery has this silver-fox energy that perfectly counters Hamm’s brooding darkness. In season one, Roger is the audience's gateway into the casual cruelty of the era. He makes a heart attack look like a minor inconvenience because he’s got a drink in his hand.
January Jones and the Betty Draper Trap
Betty Draper is arguably the hardest role in the entire show. If the actress doesn't get it right, the audience just hates her. January Jones played Betty with this brittle, porcelain fragility that felt like she might shatter if someone raised their voice. In 2007, critics weren't sure what to make of her. Was she wooden? No. She was playing a woman who had been told her entire life to be a mannequin.
The contrast between her and Elisabeth Moss’s Peggy Olson is what drives the soul of the first thirteen episodes. Peggy starts as the "mousy" secretary. Moss, coming off The West Wing, brought a grounded, almost painful earnestness to the role. While the men are playing at power, Peggy is actually earning it, one "Basket of Kisses" at a time.
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The Supporting Players Who Defined the Era
People forget how big the Mad Men: Season 1 cast actually was. It wasn't just the Drapers. You had the office ecosystem.
- Vincent Kartheiser as Pete Campbell: He was the guy everyone loved to hate. Pete is the embodiment of privilege without talent, at least early on. Kartheiser played him with this weird, high-pitched desperation that made you want to shove him into a locker.
- Christina Hendricks as Joan Holloway: She wasn't even supposed to be a series regular. Seriously. Hendricks was guest-starring, but her presence was so commanding that Weiner had to write her into the fabric of the show. She wasn't just "the secretary"; she ran that office like a general.
- Bryan Batt as Salvatore Romano: Sal’s arc in season one is heartbreaking. He’s the art director hiding his sexuality in plain sight. Batt played Sal with such subtle grace that it’s painful to rewatch those early episodes knowing where the culture was at the time.
Then there’s Robert Morse. As Bert Cooper, he provided the eccentric DNA of Sterling Cooper. Morse was a Broadway legend, and having him wander around without shoes, talking about Ayn Rand, gave the show a sense of history. It reminded us that the "Old Guard" was still watching, even as the world started to tilt.
Why the Casting Felt Different
Most TV shows in the mid-2000s were trying to be "gritty" or "fast-paced." Mad Men was slow. It breathed. The cast had to be able to handle long silences. You’ve probably noticed that in season one, there are scenes where nobody says anything for thirty seconds. They just smoke.
That requires a specific type of acting. You need faces that tell a story without a script.
Michael Gladis (Paul Kinsey) and Aaron Staton (Ken Cosgrove) filled out the creative lounge. They represented the two types of guys in every office: the one who thinks he’s an intellectual and the one who actually has a soul. Rich Sommer, as Harry Crane, started as the most "normal" guy in the room, which made his eventual slide into Hollywood sleaze even more fascinating to track from the beginning.
The Kids and the Background
Let’s talk about Kiernan Shipka. In season one, Sally Draper is just a kid in the background. Most shows treat child actors like furniture. But even then, you could see the gears turning. Shipka didn't have many lines early on, but her reactions to Betty’s coldness laid the groundwork for one of the best character arcs in television history.
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And we can't forget the original Bobby Draper. Fun fact: Bobby was played by four different actors over the course of the show. In season one, it was Maxwell Huckabee. He didn't have much to do, mostly because the show was so focused on the adults' dysfunction, but he served as the silent witness to the crumbling suburban dream.
Behind the Scenes: The Casting Director’s Gamble
Laura Schiff and Carrie Audino were the casting directors who put this puzzle together. They looked at over 80 people for the role of Peggy. They looked at dozens for Don. The budget was tight. This wasn't an HBO production with bottomless pockets. Every choice had to be deliberate.
The Mad Men: Season 1 cast succeeded because they didn't feel like "TV stars." They felt like people you’d see at a train station in 1960. There was a lack of modern "sheen" to them. Moss didn't wear makeup that looked 2007-perfect. Hamm had a haircut that looked like it was maintained with military precision.
The Legacy of the First Season Ensemble
Looking back, it’s wild to see how many of these actors became household names. Before this, Christina Hendricks was doing small arcs on sci-fi shows. Jon Hamm was literally a struggling actor about to give up.
The first season is a masterclass in ensemble building. Every character has a "ghost."
- Don has Dick Whitman.
- Peggy has her secret pregnancy.
- Pete has his family name but no money.
- Betty has her dead mother and her numb hands.
The actors leaned into these secrets. It gave the performances a layer of tension that most shows lack. When Don delivers the "Carousel" speech in the season finale, "The Wheel," the reactions from the rest of the cast are what sell it. You see the heartbreak in Harry Crane’s eyes. You see the longing in the room. It’s not just Hamm’s moment; it’s a collective realization of what they’ve all lost.
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Fact-Checking the "Unknowns"
It's a common myth that everyone was a total amateur. That's not true.
- John Slattery was an established character actor.
- Robert Morse was a Tony winner.
- Elisabeth Moss had been on The West Wing for years.
The "unknown" factor was mostly about their status as leads. Putting the show on the shoulders of Jon Hamm was the real risk. If he hadn't possessed that specific mix of charisma and self-loathing, the show would have folded in six episodes.
What to Do With This Information
If you’re a fan of the show or a student of film, don’t just watch the episodes. Watch the background. Look at how the Mad Men: Season 1 cast interacts when they aren't the focus of the shot.
- Rewatch the Pilot: Pay attention to the way the secretaries move in the background. It was choreographed like a ballet.
- Compare Season 1 to Season 7: See how much the actors aged their characters. It wasn't just makeup; it was posture and voice.
- Look for the Guest Stars: Keep an eye out for actors like Rosemarie DeWitt (Midge) who set the tone for Don’s outside life.
The best way to appreciate the casting is to realize that none of these people were "safe" choices. They were the right choices. To truly understand the impact, go back and watch the "Carousel" pitch one more time. Focus on the faces of the men from Kodak. Even the minor characters were cast to look like they were seeing their own lives flash before their eyes. That's the secret sauce of Mad Men. It wasn't about the cigarettes or the suits. It was about the faces.
Start by tracking one specific character—maybe someone like Ken Cosgrove—and watch how his facial expressions change from the pilot to the finale of the first season. You'll see the shift from boyish optimism to the first hints of corporate cynicism. That’s where the real acting happens.