The improv and sketch comedy group Upright Citizens Brigade (UCB) has become a breeding ground for many of the funniest young comedians working in film and television today. And the group has a unique origin story because it actually started out as an improv group within another improv group called ImprovOlympic (now known as iO).

Side history about iO: ImprovOlympic was originally an improv theater and training center in Chicago founded in 1981 by Del Close and Charna Halpern which used the method of theater games as a way of making improvisers compete with each other in teams. This idea was based on a format created by David Shepherd, the man who previously co-founded the Playwrights Theatre Club in 1953 as well as legendary improv theater revue The Compass Players in 1955. Shepherd introduced the concept of iO in 1972, with the first classes taking place at the Players Workshop in Chicago (Charna Halpern was an improv student at this workshop and eventually became the producer of these competitions). Shepherd and Halpern eventually moved the iO games into their own theater stage in the early 1980s. Later iO West would open in L.A. in 1997 and iO South would open in Raleigh, North Carolina, although both of those branches are now closed and the Chicago center remains iO’s sole location. Actors and comedians who have trained at iO before becoming famous include Stephen Colbert, Andy Dick, Chris Farley, Jon Favreau, Tina Fey, Jack McBrayer, Seth Meyers, Mike Myers, Bob Odenkirk, Amy Poehler, Eric Stonestreet, Jason Sudeikis and Vince Vaughn.

One group of performers that emerged from iO in 1990 was a group that called itself the Upright Citizens Brigade, which was founded by comedians Amy Poehler, Matt Walsh, Matt Besser, Ian Roberts, Adam McKay, Rick Roman, Horatio Sanz and Drew Franklin in its original incarnation. The group began performing across Chicago and they became regulars at comedy clubs before relocating to New York in 1996 where their success continued. Just like iO, they expanded into L.A., and the group even had a sketch comedy TV series that aired on Comedy Central for 3 seasons from 1998 to 2000 and another series called The UCB Show that aired on the NBC-owned streaming service Seeso for 2 seasons from 2015 to 2017.

People who attend UCB are trained in improv as well as writing, directing and honing skills in comedy and sketches, with the group’s philosophy based largely on the teachings of Del Close and the improvisational structure of the Harold, which is a long-form structure often featuring recurring characters and thematic consistency across a single show (these types of shows were popularized in California in 1967 by San Francisco-based improv group The Committee). And like I said, a lot of comedians who are working today have gotten their start on the UCB stage.

Here are some of the most notable alumni of UCB along with some of their most well-known works:

Aziz Ansari (Parks and Recreation, Master of None)

Anthony Atamanuik (The President Show)

Scott Aukerman (Mr. Show, Comedy Bang! Bang!)

Doug Benson (Getting Doug with High)

Rachel Bloom (Crazy Ex-Girlfriend)

Nicole Byer (Girl Code, Loosely Exactly Nicole)

Kay Cannon (Pitch Perfect, Blockers)

D’Arcy Carden (Broad City, The Good Place)

Cat Cohen (Three Busy Debras, Only Murders in the Building)

Adam Conover (Adam Ruins Everything, The G Word)

Rob Corddry (The Daily Show, Children’s Hospital)

Paul W. Downs (Broad City, Hacks)

Colton Dunn (Key & Peele, Superstore)

Ayo Edebiri (Big Mouth, The Bear, Inside Out 2)

Billy Eichner (Billy on the Street, Difficult People)

Cameron Esposito (Take My Wife, We Bare Bears)

Chris Gethard (The Chris Gethard Show)

Ilana Glazer (Broad City, Babes)

Donald Glover (Community, Atlanta)

Ed Helms (The Daily Show, The Office)

Lauren Holt (SNL)

Abbi Jacobson (Broad City, A League of Their Own)

Anthony Jeselnik (Comedy Central Roast, Last Comic Standing)

Ellie Kemper (The Office, Unbreakable Kimmy Schmidt)

Jordan Klepper (The Daily Show)

Nick Kroll (The League, Kroll Show, Big Mouth)

Lauren Lapkus (Orange Is the New Black, The Big Bang Theory)

Natasha Leggero (Another Period)

Riki Lindhome (Another Period, Wednesday)

Jason Mantzoukas (The League, Big Mouth, Invincible)

Jack McBrayer (30 Rock, Wreck-It Ralph)

Jessica McKenna (Party Over Here, The Mighty Ones)

Kate McKinnon (SNL, Nature Cat, Barbie)

Kate Micucci (Raising Hope, Scooby-Doo)

Andy Milonakis (The Andy Milonakis Show)

Kyle Mooney (SNL, Brigsby Bear, Saturday Morning All Star Hits!)

Bobby Moynihan (SNL)

Ego Nwodim (SNL)

Nick Offerman (Parks and Recreation, The Great North, The Last of Us)

Adam Pally (The Mindy Project, Knuckles)

Lennon Parham (Playing House, Minx)

Aubrey Plaza (Parks and Recreation, The White Lotus, Agatha All Along)

June Diane Raphael (Grace and Frankie)

Jonah Ray (The Nerdist, Mystery Science Theater 3000)

Alison Rich (The Goldbergs, The Other Two)

Sam Riegel (Teenage Mutant Ninja Turtles, Phoenix Wright, Critical Role)

Rob Riggle (SNL, The Daily Show)

Natasha Rothwell (Insecure, The White Lotus)

Jessica St. Clair (Playing House, Royal Crackers)

Paul Scheer (The League, Veep)

Ben Schwartz (Parks and Recreation, DuckTales, Sonic the Hedgehog)

Jenny Slate (SNL, Bob’s Burgers, Marcel the Shell with Shoes On)

Beth Stelling (Rutherford Falls)

Paul F. Tompkins (Mr. Show, BoJack Horseman)

Kelly Marie Tran (The Last Jedi, Raya and the Last Dragon)

Milana Vayntrub (AT&T commercials)

Noël Wells (SNL, Craig of the Creek, Star Trek: Lower Decks)

Alice Wetterlund (Silicon Valley, Resident Alien)

Jessica Williams (The Daily Show, Shrinking)

Casey Wilson (SNL, The Hotwives)

Zach Woods (The Office, Silicon Valley)

Bowen Yang (SNL, Wicked)

Sasheer Zamata (SNL, Moon Girl and Devil Dinosaur, Agatha All Along)