On September 19 that year, Professor Scott Fahlman of Carnegie Mellon University in Pittsburgh sent an email that would go on to mark the first recorded use of the divisive communication tool.
"I propose the following character sequence for joke markers: :-) Read it sideways," the message stated.
Fahlman's idea was quickly adopted on a global scale, going on to become both loved and loathed in equal measure.
There are now myriad modern incarnations of the emoticon, some animated and others with sound. Fahlman has expressed disapproval of the updated versions.
"I think they are ugly, and they ruin the challenge of trying to come up with a clever way to express emotions using standard keyboard characters. But perhaps that's just because I invented the other kind," he told The Independent.
The professor also admitted his surprise when computer users around the world began using the tool.
"This was a little bit of silliness that I tossed into a discussion about physics," he added. "It was ten minutes of my life. I expected my note might amuse a few of my friends, and that would be the end of it."
Non-digital emoticon usage can be traced back to the 19th century, when they were commonly used in casual and humorous writing.