Magna Carta

Magna Carta is a document stored in The National Archives, Archives Secure Wing East. There is a hallway to the right just before you reach Button and the Declaration of Independence. The hallway leads to a room and in the room to the far right in the Magna Carta with some ammo and two turrets. You will need Lock Pick skill of 50 for the door. It can be sold to Abraham Washington for 75 caps.

Bugs

 * If you add another Magna Carta to your inventory via console be sure to sell the original copy before, as otherwise you will not be able to sell any of them afterwards.