Jim,
Yes, I have alsop spent quite a bit of time where this attack took place - I spent some time near Fredericksburg in 1995 on an assignment for my "real" job. The 141st Pennsylvania (the Federal regiment I am making) attacked through dense woods on the south side of the Plank Road, striking the North Carolina Regiments of Scales' Brigade, A.P. Hill's 3rd Corps.
The tree trunks will be 6-inch wooden dowels on which I have sculpted bark. I did three different thicknesses - the thinnest being a coat hanger wire. These are being cast in resin, with holes drilled in them to insert dried flower branches. I found some really good scale stuff at the local Michael's.
The trees in the Wilderness are not huge, but they are closely packed and the undergrowth is very dense. However, remember that this terrain was fought over by many of the same men the afternoon before this attack, and much of the lighter undergrowth would have been beaten down by marching troops and musketry.
In addition to the resin trees, I will be making serious use of dried roots and dried basil for the forest litter. I think it will come out pretty well.
I was playing golf last week, and hit my ball off the fairway behind a dead bush that had some great branches that were perfect for the box. When the course marshal saw them in the back of our golf cart, and asked me what they were for, I told him, "Don't ask!"
Bill