The LoC has announced a new online exhibit from the American Folklife Center: “American English-Dialect Recordings: The Center for Applied Linguistics Collection”. This site has 59 audio recordings — 118 hours — covering North American English dialects. The recordings were made between 1941 and 1984, but most of them were made between 1968 and 1982. The collection’s available at http://memory.loc.gov/ammem/collections/linguistics/.
You can browse the collection by title, name, subject, or place. (There are only two main categories of place — Canada and North America — but there are lots of subcategory covering city and state.) I went and took a look at the offerings from Kentucky. There were several recordings available, some of them described as oral histories, some of them were monologues and some of them were conversations. In some cases the listings were transcriptions.
All the listings I looked at had brief descriptions of the conversations, the time the recording was made, information about the speaker, and a subject listing. All the listings also had audio available in three formats — Real, WAV, and MP3. I found a couple of the downloads a bit slow (I would rather download the recordings and listen to them that way than play them through the speaker) but once downloaded they were fascinating to listen to.