I've been wondering....why is it, that the Fallout 3 Map of of D.C. is so rife with geographic errors? After all, the timeline diverged in the 1950's...(Which doesn't explain the wrong location of many buildings etc.).

Perhaps the divergence goes back even further, but only became significant in the fifties.

As a result the city developed a lot differently.

It is canon that in fact the timeline delineated after World War II, some have pointed to the DC Wasteland being less detailed, smaller, because of the engine used by Bethesda, but much of the city is geographically correct, like the placement of important landmarks.

To my understanding, many of the landmarks in "The Mall" were incorrectly placed. Also, the Washington Naval Yard, seems to be virtually non-existent.

This is a game, not a simulation... deal.

the white house--well, what used to be the white house--isnt in the right place, but im sure people would complain about not beign able to at least check it out if it hadnt been included

I haven't gone exploring too much and I'm wondering if the White House is explorable or not?

It doesnt matter really does it? Like someone else said, it's a game not a sim. More a representation of DC for the purpose of the story

Oh yes, you can definitely explore what's left. There's a manhole cover nearby you can enter to explore the sublevels. Not really much there though, and HIGHLY radioactive..

except for that great big hunkin aircraft carrier thats a bit hard to miss....

How could he miss Rivet City? :/

Scale compression makes it hard to represent everything accurately. It's kind of the amusemant park version of D.C. (look at how small Disneyland actually is, sometime).

It is on the right place, one of the streets names is wrong and the world map icon for the White House is also wrong but if you go to the White House, turn on the no clipping and god mode cheats you can see its exactly north of the Washington monument.

As for the the National Mall ... the National Museum of American History is just replaced by the Museum of American History and the National Air and Space Museum by the Museum of Technology.

The notable difference in placement is the National Archives but its not even that off, just a one block south (were currently there is a park, considering the building is from 1935 it existed there before the divergence).