...has already been given. Talk to the group that your going to reenact with and find out their criteria & level of authenticity. Then beg, borrow, or steal from them before jumping in whole hog

As a living historian myself, I would highly recommend this article on authenticity & documentation: http://www.re-enactmentevents.com/re-enact/Proposal.php
when I first got involved in ACW (American Civil War or War Between the States) out here on the left coast, it was still somewhat of a farb fest, but there were those of us (myself included) who researched our units, & I gathered reams of 1st person documentation of what our unit (2nd Kentucky Cavalry - Morgan's Raiders) wore, utilized as weapons, & behaved generally.

Any way, read the article & follow that great advice on contacting the host group.....and have fun with it!