Nearly ten years ago, The Big Bang Theory made its debut. Starring Johnny Galecki, Jim Parsons, and Kaley Cuoco, among others, the CBS sitcom has picked up nine Emmys over its 10-season run and topped viewer ratings. See the cast of the show before they were stars, ahead.
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Big Bang Theory fans know Jim Parsons as Sheldon Cooper, a role he took on early in his career. Pictured here in 2004, Parsons made his on-screen debut in one episode of Ed in 2002. He went on to appear in TV movies and pop up as Tim in Garden Statesoon after.
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Kaley Cuoco first picked up an acting gig when she was just 7 years old, appearing in the 1992 thriller Quicksand: No Escape. Pictured here in 2002, Cuoco found success on the small screen, doing a stint on Ladies Man before booking her breakout role in 8 Simple Rules.
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Fans have known Mayim Bialik since she was a child star. The actress, who plays Amy Farrah Fowler on The Big Bang Theory, appeared in episodes of The Facts of Life, Webster, and MacGyver before leading Blossom as Blossom Russo.