what is the shield on the back of a penny
Penny (United States coin) The United States one-cent coin, often called 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 (see further below).
Penny Black The Penny Black was the world's first adhesive postage stamp used in a public postal system. It was first issued in Great Britain on 1 May 1840, but was not valid for use until 6 May. It features a profile of Queen Victoria.