For those who are looking for what has been labeled the King of Rare U.S. Coins, there is only one coin that fits this description according to the American Numismatic Society: the 1804 Silver Dollar. Today there are only 15 known examples of this coin with the strange history known to exist. According to records kept by the United States Mint, some 19,750 silver dollars were struck in 1804, however none of them were dated for that year. Instead the mint continued to use the dies from 1803. The first silver dollars to bear the date 1804 were not struck until 1834 and were requested by the Department of State to be used in presentation sets of coins that were intended to be used as gifts to be given to the various rulers in Asia in exchange for certain considerations.
They were to be a part of a set of coins that was to include two specimens of each coin that was currently in use at that time. The coins were to be made of gold, silver or copper. It is thought that since the silver dollar was still very much in use that the Mint employees decided to include them in the set even though there had been no new ones struck in 30 years. There were a total of eight of these original Class I 1804 Silver Dollars struck in 1834. One was given to the Rama II the King of Siam; one to Said bin Sultan the Sultan of Oman and Muscat; the other five were given away to unknown parties following the death of U.S. Ambassador Edmund Roberts.
One was kept and added to the U.S. Mint Collection. Today you will find that of the eight original Class I coins one is on display in the Smithsonian, one is on display in the American Numismatic Museum and the other six are said to be held by private collectors. Of these silver dollars the one given to the King of Siam has perhaps the most unusual tale. It is said that the King gave his coin to Anna Leonowens, the same Anna from the story of "The King and I," and that it was kept in her family until 1950 before being sold. From this coin the name King of Coins was attached to this the rarest of U.S. coins minted.