The NFL has had its current television blackout policy in place since Congress passed legislation in 1973 that required games be made available if the stadium was sold out at least 72 hours in advance. Prior to the legislation, the NFL blacked out all home football contests during the regular season and playoffs. Government complaints at the time eventually led to Congress implementing legislation that turned into the current NFL policy. That policy is currently under review by the FCC.
It turns out the NFL had an opportunity at the time to implement a more stringent blackout policy that would have had full White House support. Richard Nixon's White House tapes in the National Archives reveal the President offered then NFL Commissioner Pete Rozelle a compromise. In exchange for freeing up playoff games from the blackout rules, Nixon would have allowed the entire regular season to remain blacked out by vetoing any congressional legislation to the contrary. From his audio tapes:
"If you make the move, for these playoff games, we will block any -- any -- legislation to stop anything else. I will fight it personally and veto any -- any -- legislation. You can tell him that I will veto it. And we'll sustain the veto. ... Go all out on it and tell him he's got the president's personal commitment. I'm for pro football all the way, and I think it's not in pro football's interest to allow this to build up because before you know it, they'll have the damn Congress go all the way. We don't want Congress to go all the way."
President Nixon offered this compromise in part because he wanted to watch the Redskins playoff games that season. The NFL was prepared to blackout the Redskins-Packers playoff game and Nixon made the offer to prevent the blackout. President Nixon sent the attorney general to speak with Rozelle and the commissioner rejected the offer.
According to then intern and current NFL executive Joe Browne, Rozelle felt the eventual Congressional legislation was going to be a better option that would allow the league to maintain its need for sellouts, while also placating the fans.
Since the 1973 legislation went into effect, blackouts have gone down from 50% in the 1970s to six percent last season. Some teams like the Cincinnati Bengals and Tampa Bay Buccaneers still have high numbers, which is one reason the Sports Fans Coalition has petitioned the FCC for review.