First authorized on April 2, 1792 , the half cent coin was produced in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 from 1793-1857. The half-cent piece was made of 100% copper. It was slightly smaller than a modern U.S. quarter. Diameters are: 22 mm (1793), 23.5 mm (1794–1836) and 23 mm (1840–1857)., Coinage was discontinued by the Act of February 21, 1857. Every Half cent was produced At the Philadelphia Mint.

There are several different types of half cents:

• Liberty Cap
  Liberty cap
  Chiefly it refers to:*liberty cap, a brimless felt cap, such as the Phrygian cap or pileus, emblematic of a slave's manumission in the Ancient World.The phrase may also refer to:*Liberty Cap, a celebrated granite dome in Yosemite National Park...
  
  , Left (designed/engraved by Henry Voigt) - issued 1793
• Liberty Cap
  Liberty cap
  Chiefly it refers to:*liberty cap, a brimless felt cap, such as the Phrygian cap or pileus, emblematic of a slave's manumission in the Ancient World.The phrase may also refer to:*Liberty Cap, a celebrated granite dome in Yosemite National Park...
  
  , Right (large head designed by Robert Scot
  Robert Scot
  Robert Scot was the first Chief Engraver of the United States Mint from its inception in 1793 until his death in 1823. He was succeeded by William Kneass.-Early life:...
  
  , small head designed by Scot-John Gardner, engraved by Robert Scot) - issued 1794 to 1797
• Draped Bust
  Draped bust
  "Draped Bust" was the name given to a design of United States coins. It appeared on much of the regular-issue copper and silver United States coinage from 1795-1808. The denominations that featured the Draped Bust design included the half cent.-Basic design:...
  
  (obverse designed by Gilbert Stuart
  Gilbert Stuart
  Gilbert Charles Stuart was an American painter from Rhode Island.Gilbert Stuart is widely considered to be one of America's foremost portraitists...
  
   and Robert Scot, reverse designed by Scot-John Gardner, engraved by Robert Scot) - issued 1800 to 1808
• Classic Head
  Classic Head
  The Classic Head Large Cent was a type of large cent issued by the mint from 1808 until 1814. It was worth 1/100th of a dollar.-Sources:R.S. Yeoman, A Guide Book Of United States Coins 2009 Edition....
  
  (designed/engraved by John Reich) - issued 1809 to 1836
• Braided Hair (designed by Christian Gobrecht
  Christian Gobrecht
  Christian Gobrecht was the third Chief Engraver of the United States Mint from 1835 until his death in 1844. He was responsible for designing the famous "Seated Liberty" designs, which were in turn the direct inspiration for the design of the Trade Dollar...
  
  ) - issued 1840 to 1857

There are no mint marks on any of the coins (all minted at the Philadelphia Mint

Philadelphia Mint

The Philadelphia Mint was created from the need to establish a national identity and the needs of commerce in the United States. This led the Founding Fathers of the United States to make an establishment of a continental national mint a main priority after the ratification of the Constitution of...

) and the edges are plain on most half cents.