The twenty cent coin was a short-lived coin in U.S. coinage. It was minted in limited quantities from 1875 through 1878. The largest mintage was 1,155,000 in the 1875 (San Francisco).

 

Only three mints produced the 20-cent piece as follows:

• Philadelphia Mint from 1875 thru 1878
  San Francisco Mint in 1875 only
  Carson City Mint in 1875 and 1876
  

Most of the original 1876 Carson City mintage of 10,000 pieces were melted at the mint without ever being released. It's intriguing to note that a total of 1,358,890 United States 20-cent pieces have ever been minted! Today the U.S. Mint might produce that number of coins in a matter of hours.

This is in the top echelon of desirable collectibles, especially considering the relative cost and availability. Of that mintage, thousands were never to make it out of the mint. The total combined mintage of 1877 and 1878 proofs is 950 while the 1875 and 1876 proof mintages are recorded as 2,790 and 1,260 respectively.

A complete set of U.S. 20-cent pieces consists of only 9 coins. All can be obtained, with the sole exception of the 1876-CC, for under $3,000. Uncirculated examples of the San Francisco coin are available for under $500.

The three cent coin has an unusual history. It was proposed in 1851 both as a result of the decrease in postage rates from five cents to three and to answer the need for a small-denomination, easy-to-handle coin. The three cent silver featured a shield on a six sided star on the obverse and the Roman numeral III on the reverse. The coin was composed of 75% silver and 25% copper to ensure that the coin would be considered real currency yet not worth melting down for the silver. The coins were physically the lightest weight coins ever minted by the United States, weighing only 4/5 of a gram and with a diameter smaller than a modern dime and only slightly greater than the smallest gold dollars. The silver coins were known as "fishscales". The term "trimes" is often used today for these coins but that was first used by the director of the United States Mint (James Ross Snowden) at the time of their production.