Washington, D.C.

In the early 21st century, when the United States was divided into thirteen commonwealths, Washington, DC, the pre-War capital city of the U.S. became part of the Columbia Commonwealth, along with Virginia and Maryland.

Washington, DC will be one of the major locations in Fallout 3.

One of the concept art images shows the (largely intact) Capitol, while another shows the Jefferson Memorial converted to a water filtering facility. It should be noted, however, that those two images by Craig Mullins are early concept art and do not necessarily reflect the actual game.