Interesting point. I wonder though if the South had won if folks still wouldn't overwhelmingly want to portray Southerns? Something romantic about it that is more than just being underdogs. Who knows? What the heck, if the South would have won we probably wouldn't be here on FR. :-)
Snippy, Some National Park sites that do living history events also provide volunteers with everything needed to portray events. Fort Scott Kansas only requires that if you wear glasses that they be of the sort appropriate to the period. Everything else right on down to shoes, hats and gloves are in the wardrobe room for checkout. Of course, you will want to have your own undergarments. If you have never worn a corset, (I haven't!) you will want one thats fairly comfortable if possible. 19th Century womens clothing can be simple or very complicated. Its up to you and what you are portraying. You need only contact the sites in your area to find out whats available. They love volunteers.
The food is usually really good unless your in the infantry and even then it depends on how well the commisary is stocked. Some of the guys are very good at cooking. What with the fresh baked bread and vegetables I actually eat better when I'm on a re-ennactment than when I'm back in fast food land.