One of Elisabeth Moss' most iconic roles is the plucky Peggy Olson from AMC's period drama Mad Men, but there were other actresses who nearly played the character before she landed the part. When Mad Men first aired in 2007, the majority of the cast consisted of unknown actors and actresses, though their profiles were boosted considerably due to the show's popularity. Casting directors Laura Schiff and Carrie Andino helped build a strong ensemble cast for Mad Men, including Elisabeth Moss, who was mainly known for playing President Jed Bartlet's daughter Zoey in The West Wing when she got a part in the series. Though Elisabeth Moss delivered a compelling portrayal of Peggy, she definitely wasn't the only actress considered for the character.

Peggy's character arc in Mad Men is very fascinating. In Mad Men season 1, Peggy started off as an innocent and eager young woman who starts working at Sterling Cooper as Don Draper's (Jon Hamm) secretary. As the series went on, Peggy was able to rise through the ranks as a copywriter, gaining more self-confidence in the process. Her character is a very intriguing and strongly-written female role, so it's not surprising that a number of actresses were attracted to the part of Peggy.

Related: Mad Men: The Actors Who Almost Played Don Draper

Surprisingly, a few actresses who went on to have their own notable parts in Mad Men auditioned for the role of Peggy first. In an oral history of Mad Men (via TV Guide), January Jones, Christina Hendricks, and Maggie Siff admitted that they all read for Peggy's character before eventually getting cast in their series roles. Jones auditioned twice for Don Draper's new secretary on the advice of her manager, who thought the role of Betty would be insignificant due to her lack of screen time in the Mad Men pilot. However, everyone involved in the casting process, including Mad Men creator Matthew Weiner, thought she was a better fit for the "super beautiful and super icy cold" role of Betty. Weiner even wrote additional scenes for Jones to audition with after hearing her concerns about the part. Though Christina Hendricks initially landed an audition for Peggy, she realized the part wasn't a good fit for her and agreed to read for Joan Holloway. As for Maggie Siff, she and her manager decided on the day of her audition for Peggy that she should read for Rachel Menken instead.

Why Elisabeth Moss Was Cast As Peggy In Mad Men

peggy olson in mad men

The Invisible Man's Elisabeth Moss was the first actress that read for Peggy and made a strong impression on Mad Men's casting directors. Though they decided to see more actresses before making a decision for the role, Moss' first audition ended up being the best. Elisabeth Moss gained critical acclaim for this role, garnering a number of nominations as a lead actress in Mad Men. Moss effectively portrays Peggy's character arc with vulnerability and humor, proving that she was the best fit for the role all along.

While Maggie Siff, January Jones, and Christina Hendricks are all talented actresses, it's hard to imagine anyone besides Elisabeth Moss playing Peggy in Mad Men. She brings something special to the role that can't be replicated, especially in "The Suitcase," Jon Hamm's favorite Mad Men episode. Siff, Jones, and Hendricks ended up being perfectly cast for their roles as well. In the end, everyone in the Mad Men ensemble landed roles that played to their strengths and fit them well.

Next: Mad Men: All 3 Times Bobby Draper Was Recast (& Why)