Sheila asks: Do all American coins – pennies, nickels, dimes and quarters have mint marks on them? I have 30 that have no mint mark. Why is this?
United States coins dated prior to 1980 have no mint mark if they were minted in Philadelphia. From 1980, all U.S. denominations, except the cent, show a “P” mint mark if they were minted at the Philadelphia Mint.