The half cent is the smallest denomination of United States coin ever minted. It was first minted in 1793 and last minted in 1857. During its existence, it was minted with five different designs.
First authorised by the Coinage Act of 1792 on April 2, 1792, the half-cent piece was made of 100% copper and was valued at five milles, or one two-hundredth of a dollar. It was slightly smaller than a modern U.S. quarter with diameters 22 mm (1793), 23.5 mm (1794-1836) and 23 mm (1840-1857).
The first design, known as the Liberty Cap, was issued from 1793 until 1797. Production of the half cent was temporarily suspended in 1797, then resumed in 1800 with the Draped Bust obverse, which had already been in use on the silver coinage for several years. These half cents were only issued until 1808 though, after which time this "Classic Head" design was issued until 1838.
This final Braided Hair obverse design by Christian Gobrecht was introduced on the half cent in 1840 and struck until 1857. It is a re-design of the "Matron Haid" obverse which had been used on the one cent denomination since 1816. The reverse was updated too, with a wider rim and a different wreath around the value. As with all other half cent types, the coins were produced exclusively by the Philadelphia Mint.
The denomination was discontinued by the Coinage Act of February 21, 1857. While withdrawn from circulation and not used any more, the coins were never officially demonetised though. | 
