There’s a symbol we use almost daily now-a-days when we email people or tag someone on Instagram.   It kind of looks like a lower case curled inside a circle. It’s the “at sign”.   

But, even though we use it commonly for these “modern” uses, the “at sign” has been doing its job for hundreds of years, before social media, computers…in fact, even before electricity!  

Nobody knows for certain who invented the symbol, but there are several theories. One is that medieval scribes created it as a shortcut for the Latin word ad, meaning “at” or “toward.”

Another theory connects it to merchants in Renaissance Europe. In 1536, an Italian merchant named Francesco Lapi (LAH-pee) used the symbol in a letter to represent an amphora (AMP-fur-uh) , a large clay vessel that was also used as a unit of measurement for things like wine. It's one of the earliest well-documented uses of the symbol.

And eventually, the at sign became a familiar part of business. You could write something like “10 widgets at sign $2” to mean ten widgets at two dollars each.

Then, in 1971, a computer engineer named Ray Tomlinson was working on one of the first systems for sending electronic messages between computers. He needed a symbol to separate the person receiving the message from the computer where that person could be found. He looked at his keyboard. And there was the “at sign” right there above the number 2.  .It wasn't used very much, it didn't normally appear in people's names, and—most importantly—it already had a meaning that made sense: at. And that's how a symbol that had been used by merchants centuries earlier ended up becoming one of the most recognizable characters of the digital age.

So the next time you type that little encircled A, remember, it’s been saying “at” for a lot longer than you probably thought.