The final year the United States quarter was minted with a composition of 90% silver was 1964. Coins produced in subsequent years were made with a clad composition, consisting of layers of copper and nickel.
The transition away from silver was primarily driven by rising silver prices. The metal’s increasing value made it economically impractical to continue producing circulating coinage with a high silver content. Removing silver allowed the government to control costs associated with coin production and prevent hoarding driven by the intrinsic value of the metal exceeding the face value of the coin. The historical context is rooted in economic pressures and resource management during the mid-20th century.