Tradition of NFL players standing for the national anthem invented in 2009 by US military

[CentralMass]

19. I believe that this is inaccurate.. At the end of WWII the NFL Commissioner

Called for the National Anthem to be played at all games.

"President Herbert Hoover signed a bill into law making "The Star-Spangled Banner" the official anthem of the U.S. in 1931, giving the country a national anthem for the first time.
During the World War II era, with the addition of sound systems that allowed the playing of recorded music at ball games, the performance became standard and moved from the seventh-inning stretch to the beginning of the game, Ferris has said. The tradition spread to football games, too.At the end of the war, after Japan announced it would surrender, NFL Commissioner Elmer Layden called for all of the league's teams to play "The Star-Spangled Banner" at their games, arguing, “The National Anthem should be as much a part of every game as the kick-off. We must not drop it simply because the war is over. We should never forget what it stands for.”"