The United States one-cent coin (often called a penny) is a unit of currency equaling one-hundredth of a United States dollar. The cent's symbol is ¢. Its obverse has featured the profile of President Abraham Lincoln since 1909, the centennial of his birth. From 1959 (the sesquicentennial of Lincoln's birth) to 2008, the reverse featured the Lincoln Memorial. Four different reverse designs in 2009 honored Lincoln's 200th birthday and a new, "permanent" reverse - the Union Shield - was introduced in 2010. The coin is 0.75 inches (19.05 mm) in diameter and 0.0598 inches (1.52 mm) in thickness. Its weight has varied, depending upon the composition of metals used in its production.
The U.S. Mint's official name for the coin is "cent" and the U.S. Treasury's official name is "one cent piece". The colloquial term "penny" derives from the British coin of the same name, the pre-decimal version of which had a similar place in the British system. In American English, pennies is the plural form. (The plural form pence - standard in British English - is not used in American English.)