On April 29, 1999, the WWF made its return to terrestrial television , airing a special program known as SmackDown! on the fledgling UPN network. The Thursday night show became a weekly series on August 26, 1999—competing directly with WCW's Thursday night program Thunder on TBS . In 2000, the WWF, in collaboration with television network NBC , announced the creation of the XFL , a new professional football league that debuted in 2001.  The league had high ratings for the first few weeks, but initial interest waned and its ratings plunged to dismally low levels (one of its games was the lowest-rated prime-time show in the history of American television). NBC walked out on the venture after only one season, but McMahon intended to continue alone. However, after being unable to reach a deal with UPN, McMahon shut down the XFL.