Where does the number symbol come from?

The number symbol, often referred to as the "hash" or "pound" sign (#), originated from a combination of the Latin Word "libra," meaning pound, and the symbol for the unit of weight. Its use as a shorthand for "number" emerged in the United States in the 19th century, particularly in the context of typesetting and printing. Over time, it gained popularity in digital communication and social media, where it is now widely recognized as a means to categorize content through hashtags.