What would it be like to talk to someone from the Civil War era? You'd probably have a hard time understanding them. Below is a few bits of Civil War slang that might help, with the modern definitions in parenthesis.

Chief cook and bottle washer (person capable of doing many things)

Sheet iron crackers (hardtack)

sardine box (cap box)

bread basket (stomach)

greenbacks (money)

graybacks (Southern soldiers, lice)

Arkansas toothpick (large knife)

pepperbox (pistol)

Zu - Zu (Zuoave soldier)

fit to be tied (angry)

horse sense (smart, on the ball)

top rail #1 (first class)

hunkey dorey (great!)

greenhorn, bugger, skunk (officers)

snug as a bug (comfortable, cozy)

sawbones (surgeon)

skedaddle (run, scatter)

hornets (bullets)

bully (hurrah! yeah!)

possum (a buddy, pal)

blowhard (big shot)

fit as a fiddle (in good shape, healthy)

Uppity (conceited)

scarce as hen's teeth (rare or scarce)

grab a root (have dinner, potato)

tight, wallpapered (drunk)

bark juice, tar water (liquor)

nokum stiff, joy juice (liquor)

hard case (tough)

bluff (cheater)

jailbird (criminal)

hard knocks (beaten up)

been through the mill (done a lot)

quick-step (diarrhea)

played out (worn out)

toeing the mark (doing the job)

Jonah (bad luck)

goobers (peanuts)

Sunday soldiers, kid glove boys, parlor soldiers (insulting words for soldiers)

fresh fish (raw recruits)

whipped (beaten)

Sources: "The Life of Johnny Reb" by Bell Irwin Wiley, "The Life of Billy Yank" by Bell Irwin Wiley