wrong.It wasn't started during WW1.
You keep doing it because it promotes national unity.
It says there they started in 1862 during the civil war. I'm fairly confident that isn't World War I.wrong.
"The song is about a battle in the War of 1812. The first documented time that it was played at an American sporting event came at a baseball game in 1862, during the Civil War. The tradition of playing it at sports events got a dramatic boost at the 1918 World Series, during World War I. And the tradition of playing it before games was popularized during World War II."