10 early roles of 'Mad Men' actors before they were stars

... he was a struggling actor landing minor roles in episodes of "Ally McBeal" and "Gilmore Girls."

Hamm's pre-"Mad Men" acting career has become something of a legend now. He had trouble finding roles due to his "older appearance," and he was eventually dropped by his agency. He also briefly taught an acting class at his old high school in St. Louis (where one of his students was "Unbreakable Kimmy Schmidt" star Ellie Kemper).

His first credited TV appearance was "Gorgeous Guy at Bar" in an episode of "Ally McBeal."

Today, we know John Slattery as the outspoken, scotch-drinking Roger Sterling.

But he was previously most well known for guest roles on shows like "Judging Amy, "Desperate Housewives, and for playing Carrie Bradshaw's boyfriend on "Sex and the City."

January Jones is best known as Don's ex-wife, Betty Francis...

But long before that, she played "Gina" in the 2003 Adam Sandler movie "Anger Management." "Mad Men" would become Jones' breakout role.

Before Elisabeth Moss played Peggy Olson, the ad agency's best copywriter ...

... she appeared in a few TV movies and did voice-over work in cartoons including '90s hit "Batman: The Animated Series."

Moss was just 10-years-old when she lent her voice to "Batman: The Animated Series." You can spot her nearly every winter as the voice of (a young girl) alongside a singing John Goodman in "Frosty Returns."

Before Alison Brie played Trudy Campbell ...

... she made a living as a professional clown.

In something that might have informed her work on "Community" more than on "Mad Men," Brie was a clown at children's birthday parties.

You know Vincent Kartheiser as Pete Campbell, but he was in movies as a kid, too.

Kartheiser was a child star during the '90s with roles in "Alaska" and "The Indian in the Cupboard."

He could first be seen on the big screen in a minor role in "Untamed Heart."

MTV fans might have seen Christina Hendricks before she played Joan Holloway on "Mad Men"...

She nabbed her first Hollywood role in 1999 on MTV's "Undressed."

She also made an appearance in cult favorite "Firefly" as Saffron.

Before Jessica Paré became Don Draper's actress-wife ...

She was a star in her home country of Canada, starring in films such as "Hollywood/Bollywood."

She could later be seen singing once again in "Mad Men." Her performance of "Zou Bisou Bisou" in the season five premiere became a social media frenzy.

Before Rich Sommer was an ad exec on Madison Avenue...

He took bit parts in ads, including a Bud Light commercial.

Sommer says that this Bud Light commercial from 2004 was his "first NYC paid acting job." He also starred in ads for Sprint, Cingular, and Stop & Shop.

Before Robert Morse played Sterling, Cooper & Price founder Bert Cooper ...

... he was one of Hollywood's biggest musical stars in "How to Succeed in Business Without Really Trying."

His first role was in "The Secret Storm," but his most iconic one remains J. Pierpont Finch in "How to Succeed in Business Without Really Trying," where he sang such legendary songs as "Brotherhood of Man."