Steel Pennies of World War II,
In the midst of World War II the United States faced a crises as a shortage of copper hampered wartime production. Copper is a very important metal for military goods, used to produce ammunition and electronic wiring. In 1943 the US Mint ceased production of copper pennies and began production of pennies made of zinc coated steel. It is estimated that by doing so the United States saved enough copper to produce another 1.2 million shell casings for the military.