The Mint's production of coins rapidly depleted the Treasury's stock of silver. Prices for the metal were rising to such an extent that, by early June 1965, a dollar in silver coin contained 93.3 cents' worth of it at market prices. On June 3, 1965, President Lyndon Johnson announced plans to eliminate silver from the dime and quarter in favor of a clad composition, with layers of copper-nickel on each side of a layer of pure copper. The half dollar was changed from 90% silver to 40%. Congress passed the Coinage Act of 1965 in July, under which the Mint transitioned from striking 1964-dated silver quarters to striking 1965-dated clad quarters. Beginning on August 1, 1966, the Mint began to strike 1966-dated pieces, and thereafter it resumed the normal practice of striking the current year's date on each piece.