<Li> Senate agreed to House amendment on July 15, 1965 (passed) </Li> <Li> Signed into law by President Lyndon B. Johnson on July 23, 1965 </Li> <P> The Coinage Act of 1965, Pub. L. 89--81, 79 Stat. 254, enacted July 23, 1965, eliminated silver from the circulating United States dime (ten - cent piece) and quarter dollar coins . It also reduced the silver content of the half dollar from 90 percent to 40 percent; silver in the half dollar was subsequently eliminated by a 1970 law . </P> <P> There had been coin shortages beginning in 1959, and the United States Bureau of the Mint expanded production to try to meet demand . The early 1960s was a time of increased use of silver both in the coinage and in industry, putting pressure on the price of silver, which was capped at just over $1.29 per ounce by government sales at that price . The silver in a dollar's worth of quarters would be worth more as bullion than as money if the price of the metal rose past $1.38 per ounce, and there was widespread hoarding of silver coins . Demand for the Kennedy half dollar as a collectable drove it from circulation after its debut in 1964 . The Bureau of the Mint increased production, helping reduce the coin shortages by May 1965, but government stocks of silver were being rapidly reduced, and threatened to run out by 1968 . After extensive study by the Treasury Department, President Lyndon B. Johnson in June 1965 recommended that Congress pass legislation to allow for silverless dimes and quarters, and debased silver half dollars . Although there was some opposition, mainly from legislators representing Western mining states, the bill progressed rapidly through Congress, and was enacted with Johnson's signature on July 23, 1965 . </P>

When did they start putting copper in silver coins