In late-18th-century America, something of minimal value was often described as being "not worth a continental," which referred to the continental dollar, the American currency at the time of the revolution.

The continental was paper money. It had occurred to the colonists that, as their revolution was costing quite a bit to maintain, they could go into "temporary" debt to finance the war. Soon it became clear that the debt could not be repaid. Also, the printing of paper banknotes resulted in inflation. The solution? Print more of them. Further devaluation of the continental motivated the colonists to print more… then more… then still more. The continental became worthless, either for local trade or for repayment of debt.

The new country, the United States, then did something quite unusual. In its new Constitution, it created a clause to assure that this would never happen again. Under Article I, Section 10, the states were not permitted to "coin Money; emit Bills of Credit; [or] make any Thing but gold and silver Coin a Tender in Payment of Debts."