The US three-cent coin was first minted in 1851, in part because the US postage rate dropped from 5 cents to 3 cents. In the first three years of mintage, it was comprised of 75% silver and 25% copper. At 4/5 of a gram, this is the lightest coin ever minted by the US mint and with a diameter of 14mm it is almost 4 mm smaller than the modern US dime(17.9mm)
The coin was minted only in Philidelphia from 1851-1873 (with the exception of about 720,000 being minted in New Orleans in 1851).
After the introduction of the coin in 1851(type I) there were two subsequent design changes, one in 1854(type II) and one in 1859(type III)
