In December of 1941, Japanese bombers attacked Pearl Harbor. The United States entered World War II in both the European and Pacific arenas immediately after. This had a drastic effect on the price and availability of many common commodities, including metals. The U.S. Treasury changed the composition of coins it minted during the duration of the war years as a result, and some especially collectible coins like the 1943 Copper Cent exist because of it.
1943 Lincoln Cents
The bulk of Lincoln cents that were struck during 1943 were zinc-coated steel cents that over time became known as “steelies.” This is because the copper and tin the Mint had been using was needed for the war effort. To maintain the availability of cents in circulation, Congress passed a law in 1942 that allowed for this temporary change. In 1943, the Philadelphia, Denver, and San Francisco mints struck over a billion steelies combined. As a unique type of cent, these coins remain a favorite with coin collectors.