when did they quit making pennies out of copper
Penny (United States coin) In 1943, at the peak of World War II, zinc-coated steel cents were made for a short time because of war demands for copper. A few copper cents from 1943 were produced from the 1942 planchets remaining in the bins. Similarly, some 1944 steel cents have been confirmed. From 1944 through 1946, salvaged ammunition shells made their way into the minting process, and it was not uncommon to see coins featuring streaks of brass or having a considerably darker finish than other issues.
Half dollar (United States coin) By the early 1960s, the rising price of silver was nearing the point where the bullion value of U.S. silver coins would exceed face value. In 1965, the U.S. introduced layered composition coins made of a copper core laminated between two cupronickel outer faces. The silver content of dimes and quarters was eliminated, but the Kennedy half dollar composition still contained silver (reduced from 90 to 40 percent) from 1965 to 1970.