Three coin series that didn’t last long, the smallest coin made by the US, a two cent piece and a three cent nickel . The smallest is the trime, aka fish scale or three cent silver. Weighing in at a mere .8 grams (1851-1853) and .75 grams (1854 -1873) and a diameter of 14 millimeters, it is truly small. Minted in three varieties or changes in design many were melted from the last ten years of production in 1873. Proof coins were minted from 1858 to 1873 in very small numbers. The three cent nickel is a bit larger at 1.94 grams but contains no precious metal. The other was the two cent copper piece. Minted for a short ten years, it’s popularity waned in the public after the Civil War. Other coins, such as the nickel were far more popular.