Here’s the Real Reason the Dollar Sign Is an S

Updated: Jun. 02, 2022

No, the S has nothing to do with the U.S.

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Our sign for “cent,” a lowercase c with a line through it, makes cents—sorry, sense. But our much-more-widely-used currency symbol, the sign for the dollar, is based on the letter…S? How did that happen?

You may have heard that the dollar sign started as a U on top of an S, as in “United States.” Over time, the bottom of the U disappeared, leaving the S with two lines through it, which was eventually simplified to only one line. But this isn’t the true story. In fact, this symbol was actually used for another form of currency before the U.S. dollar. Here are some other myths you’ve always believed that are totally false.

The story behind this familiar monetary symbol begins not in America but in Europe. In the sixteenth century, Spanish explorers found massive quantities of silver in the South American lands they had just conquered, lands that would later become Mexico, Peru, and Bolivia. Rich with silver, Spain began minting massive quantities of silver coins called pieces of eight, or peso de ocho, “pesos” for short. The silver supply in Europe was dwindling at this time, so the Spanish peso became the primary coin for international trade.

The previous coin to hold that title was a silver coin called a joachimsthaler. The final two syllables of this mouthful of a name are actually where the word “dollar” comes from! So as the peso replaced this coin, it earned the nickname “the Spanish dollar.” Here are some more surprising facts you never knew about American money.

As the American colonies evolved, trade between Spanish Americans and English Americans became common. Merchants recording trade transactions wanted to make their lives easier by using an abbreviation for “pesos” rather than writing out the whole word. So they chose a P with a superscript S (ps), which became a P and an S overlapping, which became an S with only the stem of the P. Yup, you guessed it—an S with a line through it. Learn the stories behind 7 other symbols on our computer keyboard.

These symbols first appeared in record documents around 1770. So this symbol was around before the United States was even called the United States, a clear nail in the coffin for the “U.S.” theory. However, though the symbol comes from a Spanish coin, it was created by Americans. The English American colonists were the first to use the symbol. Since it was (in a way) already a dollar sign (for the “Spanish dollar”), and since one American dollar originally had the same value as one peso, it would eventually become the sign for the American dollar. Next, learn the reason our money is green.

[Sources:,, Observation Deck]