WASHINGTON (CNN) -- January 1 marks the 150th anniversary of the Emancipation Proclamation.
The U.S. Postal Service unveiled its new stamp commemorating the document at the National Archives in Washington.
The stamp features famous words from the document, "Henceforward Shall Be Free."It will be issued as a forever stamp. The proclamation, signed by President Abraham Lincoln on January 1, 1863, freed slaves in confederate states.
