Following is a brief chronology of the metal composition of the one-cent coin (penny):
From 1793 to 1837, pure copper.
From 1837 to 1857, bronze (95 percent copper, five percent tin and zinc).
From 1857 to 1864, 88 percent copper and 12 percent nickel, giving the coin a whitish appearance.
From 1864 to 1962, bronze (95 percent copper, five percent tin and zinc).
In 1943, most cents were made of zinc-coated steel because of the critical use of copper for the war effort.
However, some copper pennies were minted that year. You can read more about them in the next fact sheet.
1962 to 1982, 95 percent copper and 5 percent zinc (the tin was removed).
Since 1982, 97.5 percent zinc and 2.5 percent copper (copper-plated zinc).
Cents of both compositions appeared in the first year.