The Twelfth Man
Living in Seattle, you feel it is your duty to be the "12th" Man for the Seahawks… but this tradition did not start in the Pacific Northwest… it came from the state I was born in, Texas, at Texas A&M. Aggie fans stand for the entire game in honor of the players standing on the sidelines throughout the game, which lead to their 12th man status.
This tradition started at a Texas A&M game against the then-#1 ranked Centre College in January, 1922. The game wore on, ripping through all of the Aggie's reserves. The coach called in a reserve player in the press box who no longer played football (he was a basketball guy), had him suit up and stand on the sidelines in case they needed him to get on the field. The player was E. King Gill, and while they never needed him (Texas A&M won 22-14), the team and fans appreciated that he stood at the ready throughout the game. He came to be known as the twelfth man in case the 11 players on the gridiron needed him to play. Aggies loved it, and over the years, the fans adopted the habit of standing throughout the game to show their support and be the "12th Man."