I'm not sure I'd extend it that far, but personally I could see at least to Woodbridge. Another comment mentions this is based at least partially off original

I'm not sure I'd extend it that far, but personally I could see at least to Woodbridge. Another comment mentions this is based at least partially off original settlement/immigration patterns so I'm willing to be more leniant now, but at the very least inside the Beltway should be Federal entity/Capital area.