The U.S. penny is a coin worth one-hundredth of a U.S. dollar. The obverse side has depicted Abraham Lincoln since 1909, the centennial of his birth. The reverse side depicted the Lincoln Memorial from 1959 to 2008. Four different reverse designs in 2009 honored Lincoln's 200th birthday, and in 2010, a new "permanent" reverse -- the Union Shield -- was released. The term "penny" derives from the British coin of the same name.
The penny has gone through many different variations over its two-hundred year existence. Until about 1857, it was about the size of the current US dollar coin. Here are a few notable examples of the US penny:
Indian Head cent (1859-1909) - Also known as the Indian Head penny, the Indian Head cent was designed by James Barton Longacre, then Chief Engraver at the Philadelphia Mint. The obverse side features Lady Liberty with head dress. The reverse side features laurel wreath surrounding the denomination "ONE CENT."
Wheat cent (1909-1958) - In 1909, the U.S. Mint began producing a new penny featuring Abraham Lincoln, 1909 being the centennial year of his birth. A reverse design was produced bearing two wheatheads in memorial style. Between the two wheatheads, in the center of the coin, is the denomination "UNITED STATES OF AMERICA." Curving around the upper border is the national motto, E Pluribus Unum, Latin for "From Many, One."
Lincoln Memorial cent (1959-2008) - On February 2nd, 1959, a revised reverse design was introduced, commemorating the 150th anniversary of Abraham Lincoln's birth. The design features the Lincoln memorial beneath the inscription "E PLURIBUS UNUM."
Union shield cent- (2010-present) - In 2010, a new reverse design was released featuring a Union shield with "ONE CENT" superimposed on a scroll. The design once again features the motto "E PLURIBUS UNUM," depicted on the upper portion of the shield.