The three-dollar piece was a United States coin produced from 1854 to 1889. Its value was intended to tie in with the postal system. At the time, a first class postage stamp was worth 3¢, and were often sold in sheets of one hundred stamps.
Therefore, the three-dollar piece was exactly enough money to purchase a sheet of stamps. Despite this potential use, the coin was minted in small quantities, and was never widely circulated.
Authorized by the Act of February 21, 1853, the coin was designed by James B. Longacre. The obverse depicts an Indian princess and the reverse a wreath of corn, cotton, and tobacco. The three-dollar piece was .900 gold and .100 copper for a total weight of 5.015 grams.
It had a diameter of 20.5 mm with a reeded edge. Quantities were minted in Philadelphia each year of production, as well as in Dahlonega, New Orleans, and San Francisco in certain years.
Proofs were officially recorded as being minted at Philadelphia from 1859 to 1889, and only proofs were minted in 1875 and 1876. Proofs of dates prior to 1859 are also known, including extremely rare branch-mint proofs.
The total quantity of coins minted each year ranges from 2 for the 1870-S (of which only one has been confirmed to collectors) to 138,618 for the 1854.
Today, any specimen has a value of at least several hundred dollars, and the most valuable is the unique 1870-S, currently (2007) valued at $4,000,000 in AU-50.