via press release:
THURSDAY, DECEMBER 17: "THE SIMPSONS" AT 20
Thursday, December 17th. One of America's favorite -- if not entirely functional -- families first appeared on its own half-hour television show on this day 20 years ago -- "The Simpsons." Cartoonist Matt Groening's characters Homer, Marge, Bart, Lisa and Maggie soon had popularity unusual for an animated feature, and created a legion of loyal fans who wouldn't miss one of the shows. Aside from the wide range of souvenir items generated by the program, some of the character's sayings -- especially Bart's -- have become part of the language, such as "Don't have a cow." When "The Simpsons" first went on the air, there were 193 million television sets in U.S. homes -- today, the number is more than 300 million.
The Simpsons first appeared in 1987 as a series of 30-second shorts produced by Groening for the FOX series “The Tracey Ullman Show.” The first of these shorts aired on April 19, 1987, during the third week of primetime broadcasts on FOX. Soon they had their own series, premiering on FOX as a half-hour Christmas special on Dec. 17, 1989, and then as a regular series on Jan. 14, 1990.