Nobody knows for certain who invented the dollar sign. Rendered as the letter “S” struck through with one or two vertical lines, its use dates back at least to the late eighteenth century. Some have hypothesized it originated with the Pillars of Hercules appearing on Spanish coats of arms or that it derives from the intertwining of the letters “U” and “S,” standing either for “United States” or “units of silver,” but the likeliest explanation traces its lineage to the challenges of paying for the Revolutionary War. The oldest known example of the symbol that would come to serve as a stand-in for the might of American capitalism appears in the correspondence of an immigrant who worked to finance the Revolution, only to find himself largely abandoned in its aftermath by the nation he had helped bring into being.

Oliver Pollock was born in Ireland in 1737 and emigrated in 1760 to the town of Carlisle in what is now south-central Pennsylvania. Soon thereafter, he began working as a merchant based mostly in New Orleans, which was then in the process of becoming a Spanish city after the French lost the Louisiana Territory as an outcome of the Seven Years’ War. New Orleans struggled to support its rapidly growing population, even to the point of experiencing food shortages, and in the late 1760s Pollock earned the gratitude of Spanish officials by arranging for shipments of flour from Philadelphia that he then sold at a discount. Rewarded by the Governor-General of New Orleans with free trading rights throughout the Louisiana Territory, Pollock quickly became extraordinarily wealthy, mostly by trading among the ports of New Orleans, Havana, and other locales throughout the West Indies.

An early supporter of British colonial resistance to the policies of the home country, and always angling for ways to boost his fortune, Pollock was in an advantageous position to help the colonists when their protests became full-scale revolt. The American revolutionaries desperately needed money to pay for war against the British military, and while the French and Spanish governments offered financial assistance, Pollock both personally donated several hundred thousand Spanish pesos and organized a bond issue to raise funds in New Orleans. In 1777, Congress appointed Pollock as the official representative of the United States in that city, and most of the money Pollock contributed and raised went to finance the successful military campaign of George Rogers Clark in 1778 against British forces and their Indian allies in what are now Illinois and Indiana. In 1779, when Spain entered the Revolutionary War as an ally of France on the side of the colonists, Pollock became aide-de-camp for Bernardo de Gálvez, the Spanish governor of the Louisiana Territory, and in that capacity he helped muster forces and supplies instrumental to the Spanish capture of several British forts in the Mississippi Valley between 1779 and 1781.

Pollock had anticipated that his efforts in support of the Revolution would yield both profit and political influence, but instead he found himself drowning in debt when the war ended. Not only had he contributed a great deal of his personal funds, but he had also renegotiated the bond issue he had organized in a way that made him personally responsible for paying off the bonds. When creditors came calling for their money, Pollock had no choice but to declare bankruptcy in 1782. The following year, Congress appointed Pollock as a commercial agent in Cuba, and although Pollock hoped he could use that position to get back on his feet, he had creditors waiting for him there as well. He spent more than a year in a Cuban debtors’ prison before being paroled in 1785.

Pollock left Cuba and went to Philadelphia, hoping that someone in a position of power might help him recover what he had lost in support of American independence. He did find someone willing to speak on his behalf—Robert Morris, who was signatory of the Declaration of Independence and the Constitution, Superintendent of Finance for the United States in the early 1780s, and himself a financier of the American Revolution. But for years, efforts Morris made on Pollock’s behalf were to no avail. Congress refused to discharge Pollock’s debts until 1791, and although it authorized a donation to Pollock the following year, the figure was a small fraction of what Pollock had sacrificed during the Revolution.

Pollock moved back to central Pennsylvania. He ran for Congress several times, but never got elected, and although he managed to regain financial independence, becoming genuinely wealthy again eluded him. He never abandoned the prospect of being made whole by the American government, but he also never made much headway, a failure exemplified by a letter he received from Thomas Jefferson. Jefferson had been Governor of Virginia during the Revolutionary War, and Virginia’s claims to the West had extended at that time into the territory where George Rogers Clark had fought in 1778, making the state a direct beneficiary of Pollock’s efforts. But in 1811, Jefferson told Pollock that he could not help him, writing that after more than thirty years, he could no longer remember “the particulars of the transactions concerning you while I was governor.” Eventually, Pollock moved to Mississippi, where one of his daughters had married a slaveholder and plantation owner. He died there in 1823.

Largely forgotten today, Pollock does appear to have left an important legacy even beyond his support for the American Revolution. Pollock corresponded extensively with American officials during the Revolutionary War, and he kept meticulous records of his finances during the war in a series of ledgers that he gave to Robert Morris as Morris tried to make a case to Congress on Pollock’s behalf. In both his correspondence and his ledgers, Pollock abbreviated “pesos,” the currency in which he dealt most extensively and which was sometimes referred to as a “Spanish dollar,” with the letters “ps.” The letters often ran together as he wrote them, a blend that looked very much like the $ that Robert Morris began using in exchanges with Pollock to denote dollars and that became the official symbol of the currency of the United States in the 1790s.

The truth is that Oliver Pollock never set out to invent the dollar sign, and it is unlikely he was the first person whose “ps” for “pesos” mixed together in a way that looked like one. But that he commonly receives credit for doing so, an achievement often attributed to a letter dated April 1, 1778, only seems fair. After all, he expended so much of a different kind of credit on behalf of the United States, and received so little in return for it. There is an irony in making the dollar sign his legacy, but it is the least the nation could do.