There are several hypotheses as to how the dollar sign came into existence, some with a measure of academic acceptance, others the symbolic equivalent of false etymologies. One of the most popular theories is that it was used during Spanish American business correspondence in the 1770s, stemming from the Spanish American peso, also known as the Spanish Dollar or “piece of eight” in British North America.
However, another theory speculates that the sign was created by an Irishman known as Oliver Pollock, who became one of the most significant private backers of the American Revolutionary War, and invented (albeit it unintentionally) the symbol we still used today for the US dollar.
Pollock was uniquely placed to act as a financier during the Revolutionary War due to his already substantial fortune. Because America was a British colony in revolt, the British pound was unstable, so the Spanish peso became the preferred currency, and because of his business sources, Oliver Pollock was able to offer 300,000 Spanish pesos to the cause of American independence – the equivalent of $1 billion by today’s standards.
It was in one of the ledgers he sent to Congress that the origins of the dollar sign are found. According to the Historic Preservation Division Director of the Mississippi Department of Archives and History, “Pollock…entered the abbreviation ‘ps’ by the figures for ‘peso.’ Because Pollock recorded these Spanish “dollars” or “pesos” as ‘ps” and because he tended to run both letters together, the resulting symbol resembled a ‘$.’”
And so the symbol was born.