The falcons were founded in 1966 and have never won a Super Bowl.
While the Cardinals, Lions, Titans, Chargers, Browns, Bills and Vikings are older and have never won a Super Bowl, all won at least one AFL or NFL title before the 1970 AFL-NFL merger.
Congrats Falcons!
Calling bullshit on the Vikings, as while they won the 1969 NFL championship, they lost that Super Bowl to the Chiefs.