Scott,
FWIW there is a fascinating site at Fort Lee Virginia . During WW I a french 
general was brought over to design and direct the construction  of a series 
of trench/earthworks, to be used to prepare American troops for what they 
would encounter once they arrived in France. These were quite elaborate, but 
much forgotten after WWI, and were then thought to be part of the earthworks 
surrounding Petersburg 70 years previously during WBS, with which they 
intersected. Very little excavation has been done, but a surface survey has 
been completed to allow the completion of a National Register Form, which 
should be available at the Regster section of the NPS web site.

Tim T.