Predominately British copper coins and early statehood coins were in circulation before the United States Government officially minted copper coins. These early foreign and state contracted coins circulated well into the mid 1800's during the time of the U.S. Half Cent and Large Cent.
Copper coins are made for the lower denomination of exchange. The original intent of copper coinage was to be used in commerce as a metal that possesses value but of lesser value than silver and gold. Copper served this area well. Later, the discovery of adding a small amount of nickel mixed with copper created a hard wearing low value coin worthy of circulating as currency. The appearance was white in color almost like the appearance of silver, but more gray. The endurance and value of adding nickel to copper helped to eliminate the production of the three cent silver and the half dime which were two very small silver coins that were easily lost.
The largest copper coin officially minted for circulation was the British One Penny and Two Penny coin minted in 1797 and 1798. They only bear the one date 1797 and quickly lost popularity due to its enormous size and weight.