While i'm waiting for the Lonesome Road DLC, I thought it would be a great idea passing the time getting my Pip-Boy local maps as complete as possible (especially the subways). While running around the Mall I saw the walls around the Lincoln memorial and the Washington monument and got to wondering. Are those pre or post World War 3?

Sure they look crappy enough to assume they were put there by the Brotherhood or the slavers, but on the other hand according to the news snippets you find along the way, there was an awfull lot of protesting going on just before the bombs fell. So the good old US government might have placed them there to protect those landmarks.