Grant biographer Brooks Simpson was at Chancellorsville recently and notes:

The problem with popular understandings of the battle -- and this is reinforced to some extent by the NPS treatment of the field -- is that people tend to abandon interest in the battle after May 2 [1862]. The Fredericksburg battlefield is set up to interpret 1862, not the 1863 action; Salem Church is overrun by development; although there is a Hazel Grove interpretive stop and walking tours of the final Union positions, people tend to go to the Chancellorsville VC to look at where Jackson was hit (not at the monuments, by the way).

Indeed: the configuration of the park - its amenities and attractions, the accident of which lands were acquired - affects the interpretation of the the battle. An obvious point that had not occurred to me, since I don't tour with guides. Another great reason to keep park services out of the interpretation business.