During World War II, copper was needed for the war effort, prompting the U.S. Mint to produce pennies from steel coated with zinc.
Most of these pennies are common, but a few were mistakenly struck on bronze planchets intended for 1942.
The U.S. Mint's 50 State Quarters program was a collector’s dream, but the 2004 Wisconsin quarter is especially notable.
There are two varieties of this error – the "high leaf" and the "low leaf" – both of which significantly increase the coin’s value.
Most modern pennies have a narrow "AM" in "AMERICA" on the reverse side.
This error is subtle but can add considerable value to the penny. Collectors are willing to pay between $500 and $1,500 for these unique specimens.
The Eisenhower dollar, also known as the "Ike" dollar, is often overlooked by collectors.