On Mints and Mint Marks

Mint Marks are tiny letters referring to the locality where the minting of coins took place. The position of mint mark can be found typically on the back side of coins that were minted before the year 1965 and on the front after the year 1967.  

Coins of every US mint branch are recognized by mint marks.  These coin marks date back to ancient times in Rome and Greece.  

The “Director of the Mint”, through the “Act of March 3, 1835”, set rules to classify and distinguish the coins released from every US Mint branch. This core management set accurate standards and pattern of production as well as responsible coinage. 

Coins that minted at the “Philadelphia mint” earlier than the year 1979 have no mint marks. So it was in that year that the dollar was marked with the letter P and other denominations had that same mark thereafter. 

All dies for US coins are produced at the “Philadelphia Mint” and prior to shipping the coins to their mint branch, coins are marked first with the correct and designated mint markings. The precise size and positioning of the coins’ mint mark can slightly vary; this is influenced by how deep the punch was impressed and where.

The importance of mint marks:

Collectors can determine the value of a coin though mint mark, date and condition examination, making the coins condition the most significant factor and standard when determining its value.   

Defining the Mint which hit the coin is tremendously important in determining the value of the coin; the coin can be hit in huge quantities at a single Mint or in smaller quantities in another hit.

The process of minting:

1.  The making of metal strips in the correct thickness:  Zinc strips are used for pennies, alloy strips composed of nickel (25%) and nickel (75%) for nickel and dollars, half-dollars, dimes, half-dimes are fabricated from a fusion of three coatings of metals; the external layer are alloys and the center is copper.

2.  These strips of metals are then put into “blanking presses” that are responsible for cutting “round blanks”, approximately the dimension of the “done” coin. 

3.  The blanks then are softened by running them through an annealing furnace, through tumbling barrels, and then through revolving cylinders containing chemical mixtures to burnish and clean the metal. 

4.  The blanks then are washed and placed into a drying device, then into the "upsetting" machines, that produce the raised rim.

5.  The Final stage: “coining press”. Each blank is clasp into position by a collar or ring as it is being struck or hit under great pressure. Pennies need approximately40 tons of pressure and the larger coins need more. The “upper and lower dies” are stamped simultaneously on the two sides of each coin. 

The design:

The “Director of the Mint” chooses the design and pattern for United States coins, then  that is approved by the “Secretary of the Treasury”; congress can recommend and suggest a design. The design then can not be changed for twenty five years unless directed by the congress.

All emblems of United States coins minted currently represent previous presidents of the United States. President Lincoln is on the one-cent coin, adopted in the year1909; Washington on the 25 cent coin that was minted first in 1932; Jefferson on the five cent coin in 1938; Franklin Roosevelt on the dime, introduced in the year1946; Kennedy on the half dollar that was first minted in 1964.

The “Act of 1997” known as the “50 States Quarters Program” supports and allows the redesigning of the quarters - the reverse side is to show each of the fifty states emblems. Every year starting in 1999 and until 2008, coins honoring five states, having designs that are created by each state, will be issued in the sequence or manner in which each state signed the Constitution. 

The phrase "In God We Trust" was used first in 1864, on a United States two-cent coin. It then was seen on the quarter, nickel, half-dollar, silver dollar and on the $10, $5 and $20 in 1866; in 1909 on the penny, in 1916 on the dime. Today, all United States coins carry the motto.