One of five known manuscripts of Abraham Lincoln's Gettysburg Address is going on display at the Library of Congress.

Beginning Friday, the library will display the John Hay copy of the famous Civil War speech. It will be shown fox six weeks through May 4 in the "Civil War in America" exhibition.

The exhibit commemorates the 150th anniversary of the Civil War through writings and firsthand accounts. It's been extended from its original closing date in June to remain open until January 2014.

Lincoln's 1863 Gettysburg Address began with the words, "Four score and seven years ago."

The Hay copy is believed to be the second draft of the speech. Lincoln gave it to Hay, one of his two secretaries. The library holds two copies of the speech.