President Barack Obama speaks in the Oval Office of the White House in Washington, Tuesday, Nov. 1, 2011, where he signed a proclamation designating Fort Monroe as a national monument. Fort Monroe was the third-oldest Army post in continuous active service and is an important part of the history of slavery, the Civil War and the U.S. military. (AP Photo/Susan Walsh)

Photo by: Susan Walsh

President Barack Obama speaks in the Oval Office of the White House in Washington, Tuesday, Nov. 1, 2011, where he signed a proclamation designating Fort Monroe as a national monument. Fort Monroe was the third-oldest Army post in continuous active service and is an important part of the history of slavery, the Civil War and the U.S. military. (AP Photo/Susan Walsh)