On April 11, 2012 the National Archives of the United States will commemorate the 150th anniversary of the Emancipation Proclamation. For information on this commemoration, visit this release from the National Archives: National Archives Commemorates the 150th Anniversary of DC Emancipation Act April 11.
You can get more information on the Emancipation Proclamation in the library’s collection under the search “emancipation proclamation.” The National Archives has created an online exhibit and information page on slavery in Washington, DC at this address: http://www.civilwardc.org/. Here is a short video about their documents and their work: