Happy 60th birthday to the Hook'em Horns sign.

When the Longhorns hosted TCU on Nov. 12, 1955, it was the first time that the now globally recognized hand sign was flashed at a Texas football game.

On the night before the game, Texas head cheerleader Harley Clark introduced the sign at a pep rally.

"This is the official hand sign of the University of Texas, to be used whenever and wherever Longhorns gather," said Clark, who devised the sign with his friend Henry Pitts.

The clip above was shot at Clark's home outside Austin in September 2013. It is believed to be the last video interview Clark gave regarding the Hook'em Horns sign before his passing in October 2014.

Last month, Hook'em Horns got its own emoji when Apple released its iOS 9.1 update.

The Longhorns lost that game to eighth-ranked TCU 47-20, but the tradition was born.

Related Story: The Passing Of Harley Clark