Danny,
What you seem to be describing is an old growth forest where there was little "ground cover" because the tall trees blocked the sun. Still in areas where the forests had burned from lightening strikes (or even in areas Native Americans did somewhat controlled burning for agriculture) or in areas close to streams or swamps, there would have been and still are very thick piles of brambles and ground cover - at least here n Virginia. Also, on the edges of old growth forests, there was still a lot of ground cover even back then.
I think Gary Brumfield got a degree in forestry unless I'm mistaken. Perhaps he could give better information on the forests in Virginia of the time period.
TOF,
I agree the fringe on Riflemen's shirts would have and still do pick up all kinds of "stuff" in the woods around here. I used to hunt a lot in Nottoway and Amelia Counties and in a days hunt in some areas, the fringe would be full of "stuff" depending on the time of year - especially around swamp or marsh areas. That's another reason I only had one fringed rifleman's shirt over the years.
I think someone explained in an earlier thread that the fringe would have a tendency to wick away moisture. If that's true, that and breaking up a person's silhouette would be the most practical reasons for the fringe I know of.