Bamabill's advice is good. Research is the key. Armies stuck mostly to the roads and almost always camped near water.
Maps of the period are necessary. Many are available for free on the internet. You'll be surprised how many roads existed back then that are all but gone now. Same with the creeks and streams - especially if you're in an area where modern development has changed the topography.
I live in a suburban area where there's not much open space left. I got permission to hunt a 1 - 2 acre field with an 1880's house on it. Talking to the owner, she said there used to be a creek before the modern houses were built in the 1970's. There is NO sign of it now. Sure enough, I found bullets and buttons and horse tack - even an arrow head - on the lot.
Good luck,
DCMatt