In America during the late 1600s through early 1700s fiat currency was placed into circulation as the loan or mortgage held by the governor secured by the property of the borrower. There was no promise, advertisement, or intention to pay in metal. In a public land loan office system, the value of the currency is backed by the value of the property which the borrower does not wish to lose if they fail to collect back currency in the same unit of account after spending and investing to avoid default or foreclosure.
The promise which governors and colonial assemblies made to the borrowers was primarily that the government would continuously spend the revenues brought in by interest payments back into circulation on local infrastructure, and that new loans would be regularly issues at low interest rates of 3-4%, so that the money needed by borrowers to repay their debts was easy to come by, and that the debt would not be held or sold to private lenders engaged in usury.
So accepting the scheme was a good deal to borrowers, and provided immigrant farmers with cash & credit which would not otherwise be available to them without borrowing form European lenders at high rates. The government acted as a public bank and the money was a public utility.