Old Southern main mileposts....

[cobra30689]

Today's Piedmont Division mileposts begin from Washington DC (the signal at VAL being 9.2 on the North Passenger track, and CR Tower at 10.7 from the Horn)....was that always the case even in the Southern era, or did they begin from the old yard at Duke St. in Alexandria (similar to how the NEC mileposts from HUDSON to ZOO start at the old Exchange Place terminal in Jersey City, long gone...not NY Penn Station) and eventually renumbered?

[train2]

I am fairly certain that 0 mile post was considered Washington DC (union station). I can't say for the predecessors to SR but the miles post have not been renumbered in my life time. In fact VAL is a relatively new signal, post NS and I think put in only when CSX redid AF interlocking.