Peele regularly performed at Boom Chicago in Amsterdam and The Second City in Chicago. He and Nicole Parker were well known for their musical duets at Boom Chicago. He portrayed a popular character called "Danish Supermodel Ute" during his time at Boom Chicago and hosted MTV's Comedy Weekend in 2002.  In 2003, Peele joined the cast of Mad TV for its ninth season. Around the time Keegan-Michael Key joined the cast as a featured performer, it was assumed that Key would be chosen over Peele. The two of them ultimately were cast together after showing great comedic chemistry. Peele performed celebrity impersonations, which included favorites Caroll Spinney (as the voice of Big Bird from Sesame Street), Ja Rule, James Brown, Flavor Flav, Justin Guarini, Montel Williams, Morgan Freeman and Forest Whitaker. Peele was absent from the first four episodes of his second season on Mad TV. He made a cameo in "Weird Al" Yankovic's video "White & Nerdy" with Mad TV co-star Keegan-Michael Key.  Peele was nominated for a 2008 Emmy Award for his song "Sad Fitty Cent", a music video parody about 50 Cent lamenting over his rivalry with Kanye West. The lyrics were, according to the music video, written by Peele, and he was involved in arranging its music. In 2009 he appeared in Little Fockers.  Peele appeared in a viral video titled "Hillary vs Obama" (which was shown as a Mad TV sketch) where he and a Hillary Clinton supporter (played by short-term cast member Lisa Donovan) argue over whether Hillary Clinton or Barack Obama would make a better president, only to get upstaged by a Rudy Giuliani supporter (played by Donovan's brother, Ben). Peele auditioned to be a castmember for Saturday Night Live when SNL producers were looking for someone to play Barack Obama (around the time when SNL and Mad TV -- and other scripted shows -- were put on hiatus due to the 2007-2008 Writers Guild of America strike). Peele remained at Mad TV and the role went to Fred Armisen until September 2012, when Jay Pharoah took over the role.  After five seasons on Mad TV, Peele left the cast at the end of the 13th season.

Answer this question "What did he do before MAD TV?" by extracting the answer from the text above.
Peele regularly performed at Boom Chicago in Amsterdam and The Second City in Chicago.