The shotgun evolved from the single wing and the similar double-wing spread; famed triple threat man Sammy Baugh has claimed that the shotgun was effectively the same as the version of the double-wing he ran at Texas Christian University in the 1930s.

In the latter part of the 1940s, the Philadelphia Eagles, under Hall of Fame Coach Earl “Greasy” Neale, implemented the shotgun formation in their offensive attack with quarterback Tommy Thompson.

The formation was named by the man who actually devised it, San Francisco 49ers coach Red Hickey, in 1960.[2] John Brodie was the first NFL shotgun quarterback, beating out former starter Y. A. Tittle largely because he was mobile enough to effectively run the formation.

The shotgun was briefly used by the New York Jets during the middle of the Joe Namath era, as documented in the 1971 Sporting News article “Joe and the Booyah Tribe”, to give the bad-kneed, and often immobile quarterback more time to set up plays by placing him deeper in the backfield. But the formation was not again used on a regular basis until the 1975 season, and then only by the Dallas Cowboys, which used the shotgun frequently with Roger Staubach at quarterback. The Cowboy shotgun differed from the 49er shotgun as Staubach generally had a back next to him in the backfield (making runs possible), where Brodie was normally alone in the backfield.

Since no other NFL teams used the formation during this time, some believed it had been invented by Tom Landry. Instead, Landry simply dusted off the old innovation to address a pressing problem: keeping Staubach protected while an unusually young and inexperienced squad (12 rookies made the 1975 Cowboys roster) jelled. The team ended up in the Super Bowl, in no small part due to its new use of the old formation. The shotgun became a “signature” formation for the Cowboys, especially during third down situations.

The shotgun was adopted by more teams throughout the 1980s, and was part of almost every team’s offense in the pass-happy 1990s.

article taken from wikipedia