From The Great American Meat Book, by Merle Ellis

A few words on "Country Ham":
The hams found in most city supermarkets these days are the well-dressed, water-added, mild-mannered, debonair, but distant city cousin of the old-fashioned "country ham," common a generation ago. "City hams," as I like to call them, have much to commend them, but little to distinguish them one from another with the exception of the package they come in.

Most city hams are water-added. The curing ingredients - salt, sugar, sodium nitrate, etc. - are dissolved in water and pumped into the leg of pork. Some water remains in the meat after the processing. They are mild in flavor and preferred by many of today's consumers, but to my taste they cannot compare to an old-fashioned country ham.

Country Hams are "dry-cured". The hams are "put down", in curing rooms, packed in salt mixed with the other curing ingredients. they are left for up to thirty-five or forty days. The salt draws much of the moisture out of the meat, yielding a firmer, somewhat salty, but very flavorful finished product.

Here are some sources:

Burger's Country Hams
Hwy 87 S.
Califonia, MO 65018
800-624-5426

Clifty Farms/TN Valley
Country Hams
PO Box 1146
Paris, TN 38242
800-486-4267

Craver's Country Ham House
900 Thurmond Street
Winston-Salem, NC 27105
800-898-7675