David Letterman arrives at the Kennedy Center for the Performing Arts for the 20th Annual Mark Twain Prize for American Humor presented to him on Sunday.
Owen Sweeney/Owen Sweeney/Invision/AP
Conan O'Brien in 2016. He is being sued by a writer who accuses him of stealing jokes. O'Brien says the idea of stealing someone else's comedy makes him physically ill.
Tim Mosenfelder/Getty Images
Groundlings comedy troupe founder Gary Austin has died at 75. Here he attends a January 2016 Groundlings event with actress Victoria Carrol-Bell in West Hollywood, Calif.
Araya Diaz/Getty Images for The Groundlings
Comedian Irwin Corey was known for his long-running act as "The World's Foremost Authority." He is pictured here in the 1970s. Corey died at the age of 102.
ABC/Michael Ochs Archives/Getty Images
Corey Ryan Forrester, Drew Morgan and Trae Crowder write and perform together. They wrote a book called The Liberal Redneck Manifesto, which challenges what readers might expect from Southern comedy.
Robin Marchant/Getty Images