Head of State

 is a Fallout 3 quest. It is also an Xbox 360 and PC achievement.

Objectives and Walkthrough
The quest is given to you in Temple of the Union by Hannibal Hamlin, who wants to relocate his slave haven to the Lincoln Memorial and restore it as a sign of freedom.

Hannibal directs you to travel to the Lincoln Memorial and see if it is still occupied by Super Mutants. He also asks you to talk with fellow slave Caleb Smith. Smith is a mason and will ask you to obtain a picture of Lincoln Memorial in the Museum of American History so he will have reference materials that will help him repair it. The poster is at the top of the stairs above a desk in the museum office area where there is a turret gun.

Lincoln Memorial is free of mutants, but occupied with slave hunters from Paradise Falls led by Leroy Walker. In talking with Leroy, the player is given the option to reveal the slave hideout in Temple of the Union.

The quest can also be started by speaking to Leroy Walker in the Lincoln Memorial Maintenance area without speaking to Hannibal. The player will be asked to retrieve artifacts related to Lincoln in the History Museum. However, Leroy may go onto the restricted part of the memorial thereby preventing you from selling the artifacts to him because the slavers will turn hostile, including Leroy. Talking to Salis will allow you access to the back room where Leroy is waiting to talk.

If the player reports back to Hannibal that there are no mutants, he will gather up his group and head for the memorial. He tells you to wait an hour and they will be ready. (If you fast travel to the memorial without waiting an hour, the group will not arrive until you fast travel back and trigger their departure.) If your strength is high enough you have an option to warn about the slavers, at which point Hannibal tells you to take care of them by any means.

Once the slaves arrive, they will ask for your help killing the slave hunters. If the player does not tell Hannibal to wait while you check it out (giving you time to go kill the slave hunters), then Hannibal will lead his group into battle. He is usually killed, which terminates the quest. However, if you "investigate" and kill the slave hunters, or have already done so, there will be no one to kill Hannibal when he leads the charge and the player can complete the quest.

Unable to Finish Quest (with fix)
If you kill slavers first and tell Hannibal about it, quest can be bugged. Save your game before talking to Hannibal, talk to him, and wait 1 hours, then go outside and stay there till they gather and start marching. Then, do not fast travel to Memorial itself, instead, travel to nearest metro station (Mall Northwest). It's also shown as a quest marker on your map. When you travel there, he and his pack will be there and you get quest completed (If his he and his men are not there, just WAIT around for a couple of hours and he'll get there). And be sure that metro station entrance is clear, otherwise, he'll attack whatever nearby and start marching to the completely wrong direction.

It appears that the undocumented next part of the quest is to escort Hannibal to his new sanctuary. You can ask him to wait while you scout ahead. He will travel through the subways - if you are willing to babysit him he will show a few locations. Beware near Farragut where there is a minor skimish taking place between Raiders, Talon forces and Super mutants. So long as he is on the road, you can fast travel to the quest target and then wait for a few days for him to turn up.

In short, do not fast travel to Memorial itself and be sure that it is clear around metro station.

Unable to unlock Xbox 360 Achievement (with fix)
If you kill the slavers and the mutants first, when you first arrival at the Temple of the Union, you can have a step (Talk to Hannibal Hamlin) that never gets updated, preventing you from getting the achievement. This happens when Hannibal Hamlin first talks to you if you ask him questions before receiving the Head of State quest. The workaround:

When you first go up the steps and Hannibal Hamlin talks to you automatically, feel free to talk to him but do not ask "why are you holed up" as this is what creates the bug. Tell him you are done and you will receive the Head of State quest. Then speak to him again and you will receive the update for talking to Hamlin. At this point you can talk to Caleb to complete the next step, and then move on to collect the poster. Mention the mutants being dead to Hannibal before turning the poster in to Caleb, then turn the poster in, then tell Hannibal that the slavers are dead, then wait an hour and fast travel the the memorial or NW Mall and speak to hannibal to get the quest completed and the achievement.