You'll Never Guess Why the Dollar Sign is an S

While it's usually pretty easy to figure out where our most common symbols come from, the dollar sign ($) might not be so intuitive. Take the trademark symbols, for example: ® means registered; © means copyright; and ™ means trademark. Fahrenheit (°F) and cents (¢) are equally easy to understand. Then how did we begin using an uppercase S with one or two lines through it ($) to represent the U.S. dollar sign? Read on to learn the full history of how the dollar sign came to be the iconic symbol of money we know today.

Dollar Sign Theories

While the dollar sign does not have a definite origin, there are a couple of theories as to how it came to be.

Theory #1: Ayn Rand and the Dollar Sign

One popular origin story is credited to famous author and philosopher Ayn Rand. In her 1957 dystopian novel, Atlas Shrugged, the heroin protagonist explains to another character what the dollar sign stands for. In her reply, she states: "Incidentally, do you know where that sign comes from? It stands for the initials of the United States."

The dollar sign started as a U on top of an S, as shorthand for "United States."  Over time, the bottom of the U disappeared, leaving the S with two lines through it. Later it was simplified to only one line. That makes sense, right? Unfortunately, Rand's claims about the history of the dollar sign may not be accurate since there is evidence of the use of the dollar sign before the United States was inaugurated as a nation in 1776.

Theory #2: Spanish Origins

The most widely accepted story, however, is a bit more complicated, and it begins in Europe. The tale begins in the sixteenth century, when Spanish explorers found massive quantities of silver in their newly-conquered South American lands—lands that would later become Mexico, Peru, and Bolivia. Swimming in silver, Spain went to town minting silver coins known as "pieces of eight," or peso de ocho— "pesos" for short. And so the "Spanish dollar" was born.

Rather than write out the whole word, merchants began using a P with a superscript S (P^s) as an abbreviation for "pesos." Over time that morphed into an overlapping P and S, which eventually became an S with only the stem of the P: An S with a line through it.

According to the U.S. Currency Education program, the U.S. officially adopted the dollar sign in 1785, and notes that the, "symbol evolve[d] from the Spanish American figure for pesos" The Spanish dollar remained a legal form of tender in the United States until February 21, 1857.

Now, the good old $ sign is nearly as iconic as the American flag… and you can take that to the bank!