Pennies without mint marks are made in Philadelphia PA.
However, when demand warrants, the San Francisco and/or West Point Mints have been pressed into service to mint extra cents. These are also made without mint marks to avoid creating instant rarities, and are indistinguishable from their Philadelphia counterparts.
None of them will have mint marks.
The "Crown" and the "Castle" are two of many mint marks types indicating where the item was made or minted. The Mint Marks are many and varied. There are at least three different "Castle" mint marks and two different "Crown" mint marks. Other mint mint marks include crosses, stars, flowers, moons, keys, animals, etc. all of which have many variations, and these are only the British marks.
No, not all gold coins have dates and mint marks. It depends on the specific coin and minting process.
Yes, all the silver war nickels have mint marks, even Philadelphia. There will be a large letter P, D, or S above Monticello.
Check that coin again. Mint marks were on all quarters by 1981.
25,771,428,376
Nowhere, because all shield nickels were minted in Philadelphia.
In general, "S" mint marks from the San Fransisco mint are more scarce than other mint marks when it comes to pennies. But just because it has an "S" on it doesn't make it a rare, or even scarce coin.
One cent. Please check your pocket change. While all other denominations carry mint marks, the only circulating cents that bear a mint mark are from Denver. Those minted at Philadelphia (and occasionally at West Point) do not have mint marks.
Mint marks on all Lincoln cents from 1909 to the present are located directly below the date. If it doesn't have a mint mark, that means it's from Philadelphia.
For most US coins, it means the coin was minted at Philadelphia before 1980, when the P mint mark was adopted. Cents minted at Philadelphia and West Point don't have mint marks, and all coins dated 1965 through 1967 don't have mint marks regardless of where they were produced.
No - there are three types ... 392,021,000 with no mint mark 57,154,000 with D mint mark 57,154,000 with S mint mark for 1919 USA 1 Cent. The mint mark (if present) is below the date.