Joe Mantegna Pictures: The Simpsons: Treehouse of Horror XX and 20th Anniversary Party Photos
Joe Mantegna arrives at "The Simpsons: Treehouse of Horror XX" and 20th anniversary party held at the Barker Hangar on October 18, 2009 in Santa Monica, California.
Homer, Bart, Lisa, Marge and Maggie Simpson were all on hand to celebrate 20 years of "The Simpsons." Their series is the longest-running American sitcom, the longest-running American animated program, and it recently surpassed "Gunsmoke" as the longest-running American primetime scripted entertainment program.