Mistakenly listed as the worst franchise in NFL History. Only known for performances in last few decades, never given consideration for the above average performances for the other approximately 60 years of franchise history.
Franchises considered to be worse, starting from the worst:
Cardinals-First from Chicago, then St. Louis, then, Phoenix, now Arizona. Most losses. In their 80 years of existance... 8 playoff appearances. No one wants them.
Saints-AKA 'Aints'. Only recently have their performance turned around, thanks to Drew Brees.
Texans-Haven't been around that long, but their performance is still horrible other than VERY recent. Worst winning percentage at 33.3%.
Falcons-Despite recent performances and their famed 1977 defense. Nothing. Riddled with losing seasons and scandals.
Bengals-No Championships, losing record. Only 12 winning seasons of 40.
Buccaneers-Home of the FIRST defeated team 0-14. Second Worst Win Percentage 39.3%. Their only Superbowl win is considered a fluke.
Bills-They missed the Superbowl win four times in a row.
Seahawks-No championships even with a great coach. Only team to go to the playoffs with a losing record.
Detroit Lions-Not the best team, but not the worst. With four championships although many, many years ago. Failures to win in the playoffs except once since 1957, and of course no Superbowls. Even if they are the few to yet win one, and to have a defeated season 0-16. I feel, though, the Lions are emerging from the abyss to become a contender for decades to come.
I would list a site which gives extremely detailed and accurate information, but it's cold hard football facts dot com. hint hint.