The United States one-cent coin (often called a penny, from the British coin of the same name) is a unit of currency equalling one-hundredth of a United States dollar. The cent's symbol is ¢. It has been the lowest-value physical unit of U.S. currency since the abolition of the half-cent in 1857.
The earliest one cent coins were large and made of copper. Their designs changed relatively often; there were three different types in 1793 alone, the Flowing Hair / Chain Cent, the Flowing Hair / Wreath Cent and the Liberty Cap Cent - the latter issued until 1796, after which came the Draped Bust type (1796 to 1807), the so-called Classic Head Cent (1808 to 1814) and the Coronet Cent, also known as Liberty Head (1816 to 1857).
When a large copper coin became impractical, an alternative was sought. The Flying Eagle cent was a transitional smaller type, struck between 1856 and 1858 in copper-nickel. This design was short-lived and was replaced by the the Indian Head type in 1859 - initially also in copper-nickel until 1864, then bronze.
In 1909, the Lincoln Cent (also known as a Lincoln Penny) was introduced to mark the centenary of the birth of Abraham Lincoln, the 16th president of the United States. This was the first time when an actual person (and not an abstract symbol such as Liberty) was depicted on American coins. The obverse of the coin shows a portrait of Abraham Lincoln by Victor David Brenner. The original reverse, also by Brenner, showed the value surrounded by wheat stalks and is known as the "Wheat Penny"; this was issued for 50 years until it was replaced by the depiction of the Lincoln Memorial in 1959, to mark the 150th anniversary of the birth of Abraham Lincoln. In 2009, four different reverses were issued to mark the various stages of his life (known as Lincoln Bicentennial cents, commemorating 200 years since his birth). After that, the reverse changed again and now depicts the Union Shield of the United States.
The designer's initials VDB appeared on the reverse for a short while in 1909 but were deemed too prominent and were almost immediately removed; in 1918, they were restored to the obverse of the coin where they still are - on the truncation of Lincoln's shoulder.
The material of the coin also changed. Originally struck in 95% copper, the cent coin was changed for one year to zinc-coated steel in 1943 as copper was needed to aid in the war effort. The mint then reverted to 95% copper until 1982, when inflation made copper too expensive and the composition was changed to zinc with an outer copper layer.