The final instance of United States circulating coinage composed of ninety percent silver occurred in 1964. This applied specifically to dimes, quarters, and half-dollars. These coins, valuable for their intrinsic metal content, ceased to be produced for general circulation due to rising silver prices.
The historical significance of this transition lies in the shift from precious metal-backed currency to fiat currency. The increasing cost of silver made it economically unsustainable to continue producing coins with such a high silver content at their face value. Retaining these coins is an avenue for collectors and investors interested in precious metals and numismatics.