when did the us government stop using silver in coins
Coinage Act of 1965 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.
History of the United States dollar Thus the United States moved to a gold standard, making both gold and silver the legal-tender coinage of the United States, and guaranteed the dollar as convertible to 1.5 g (23.22 grains) of gold.[10]