For revolutionary war, if you live on the East Coast, contact the Brigade of the American Revolution. If in the midwest, then the North West Territory Alliance at http://www.nwta.com
Civil War you also have choices. The North South Skirmish Association ( http://www.n-ssa.org
or their recruiter at email@example.com) or the Civil War Skirmish Association (West Ccoast) at http://www.calweb.com/~arline
for more info.
I know some reenactors (French Indian & Napleonic) and the task requires a lot of dedicated work and research for authenticity. By the way, for either war, get use to hardtack and don't forget to rap it smartly against the table to shake out the worms or weavils. While you won't face death
, you don't get to pillage and burn either.
Vigilantibus et non dormientibus jura subveniunt