Washington – The document that freed slaves held in the U.S. South celebrates its 150th birthday on Tuesday, and to mark the occasion, the National Archives has put it on display. 

President Abraham Lincoln issued the Emancipation Proclamation on January 1, 1863, declaring all slaves in Confederate territories, the rebellious southern states, to be “forever free.’’ 

The proclamation led to the ratification of the 13th Amendment to the constitution in 1865, which legally ended the institution of slavery across the U.S. Several hundred people lined up on Sunday in Washington to view what the National Archives called “one of the great documents of human freedom.’’ 

Two of the original five pages of the document are on display through Tuesday in a plexiglass case in the rotunda of the National Archives buiding. 

The tumultuous period in U.S. history during which the Emancipation Proclamation was written and signed is also the subject of the current major motion picture Lincoln, starring Daniel Day Lewis, which has been nominated for multiple awards. 

Historian Doris Kearns Goodwin, whose books provided the basis for the movie and who collaborated in its production, said on NBC News on Sunday that, philosophically, Lincoln always believed slavery was wrong. The question he had to resolve, she said, was what power did he have to abolish it. 

The Emancipation Proclamation was not passed by Congress but was a military order Lincoln issued as commander-in-chief of the U.S. armed forces. It brought freedom to slaves in areas under the control of Lincoln’s Union army. 

The National Archives is the nation’s record keeper. It also keeps original copies of the Magna Carta and the Declaration of Independence. 

The Emancipation Proclamation can be displayed only for a limited time because of its fragility, which can worsen by exposure to light, the archives said. 

The archives is to cap its three-day display with a public reading of the proclamation on Tuesday.