To start this quest talk to Abraham Washington in Rivet City, Midship deck. The National Archives are near the washington monument. Travel there (if you haven't found it yet I suggest doing "Galaxy News Radio" quest at the same time as this one. If you face the capitol building the national archives are down one of the streets to the left hand side. Go in and forward to meet Sydney who is also trying to find the declaratuion of Independence. She can show you how to find it, but you have to split the reward with her (I did it this way I don't know about the other ways). Agree to team up and use the the computer behind her to access a hidden elevator in the floor. Take this down, and make your way forward (it's pretty self-explanatory if you've got Sydney with you) Either kill the robot at the end or go to arlington library to get ink for good karma (much easier to kill him). Use his computer to open the door at the back. Open the middle safe, grab the decleration and get out of there. Fast travel to rivet city to get your reward.