• Mintmarks appear on commemorative and bullion coins

• Some mint marks are in the form of monograms or letters

• Coins produced in small mintages that are in the best possible condition (very clearly defined designs, highest luster and minimal markings) command the highest prices.

• When US coins are found with a date only and no mintmark, this usually means this type of coin was minted in Philadelphia. These type of coins are often called 1927-P and have been found primarily after the 1960's

• The Philadelphia mint is the oldest and most prolific, however branch mints sprung up near caches of precious metals or port towns like in New Orleans (known as "O") in 1838 and Charlotte, NC (known as "C") and Dahlongega, GA in the early 1800s.

• The California Gold Rush led to the founding of the San Francisco mint in 1854

• If the coin is dated 1964 or earlier the mintmark is found on the backside of the coin

• Some coins such as the 1927-S, are an extremely valuable coin, quite rare and are often valued at the six figure pricing, while other US coins from a more common mint state, like the pre-Civil War Philadelphia coin, are less rare, but still maintain value.

• Pre-1933 gold coins were struck at all US mint locations, but not all mintages are alike.

• Pre-1933 gold coins were minted in specific denominations: $1, $2.50 (quarter eagle), $3, (stellas), $5 (half eagles), $10 (eagles), and $20 (double eagles).

• The most exceptionally designed pre-1933 gold coin is the St. Guadens, minted from 1907-1933. President Theodore Roosevelt commissioned sculptor Augustus St. Gaudens to devise a coin equal in beauty to the classical ancient coins he so admired.