The Half Dime is an American silver coin with a face value of five cents which was minted between 1794 and 1873. These coins were much smaller than dimes in diameter and thickness, appearing to be "half dimes" and are called so, even though until 1837 this was not actually spelled out on the coins themselves.
After the initial issue of a "Half Disme" in 1794 (note the additional S in the name) - which many people consider a pattern, this "Flowing Hair" type of the half dime was introduced in 1794. It features on the obverse a portrait of Miss Liberty with her hair flowing freely behind her, giving the design its name. The design is the same as on the larger denomination of the same period and, given that the value and denomination are not written on the coin, they have to be inferred by size only.
The design was short-lived and was only issued for two years, after which time it was superseded by the Draped Bust type in 1796.
The silver format of the half dime was discontinued in 1873, but the coins have never been demonetised and are still legal tender. This, of course, is of academic interest only, as their numismatic value is enormously higher than their face value.