The United States Congress nearly agreed to mint a twenty-cent “double dime” coin in 1806, but the idea was voted down in the end. In 1875, the idea was brought up again, and this time passed. For four years, twenty-cent coins made of silver were minted but were an almost instant failure. They looked too much like 25¢ quarters, and there was simply no need for them.
After two years, the coins were withdrawn, though there were collectors-only twenty cent coins minted for an additional two years. Many of the circulating coins were melted down by the government, and especially nice examples of these silver coins (uncirculated or high-grade pieces) can go for quite high prices. Even run-of-the-mill 20¢ coins of 1875-1878 can be somewhat expensive, but there are usually several for sale at any given time that are in the realm of affordability for most collectors.
See also: Singapore Rare Coins: Great Collectibles from All Eras
Collectors love the rarity and the somewhat obscure history of the U.S. twenty-cent coin experiment, and the coins have a small but devoted following in the collecting world. Fans of silver coins, outmoded denominations, failed experiments, and United States numismatics in general will love to search the current for-sale listings of 20¢ coins from a large variety of sellers. The offers are updated daily, with listings frequently added and removed.
