X is believed to be of ancient Roman origin. While in modern times it was first seen in the painting The Oath of the Horatii (1784) & from there it was popularized by movies like Ben-Hur & Cabiria.
By 1923, X was picked up a particular party & was made mandatory for all party members. It functioned as a display of commitment and a declaration of principle to the outside world.
What am I talking about?
Show Answer
Nazi Salute
In 1892, Francis Bellamy introduced the American Pledge of Allegiance, which was to be accompanied by a visually similar saluting gesture, referred to as the Bellamy salute. Because of the resemblance between the American Bellamy salute and the Nazi salute, it was replaced in 1942 by a hand-over-the-heart gesture to be used by civilians during the Pledge of Allegiance and the national anthem.
Read More about the history of the gesture.