Like traditional American folk songs, I really don't know anything about it
I tried to listen to the volume 2 and 3 but didn't liked it at all
Smithsonian Folkways
Anthology of American Folk Music
https://www.youtube.com/watch?v=ICXYMjgmG88
https://youtu.be/hvJ6M0Oz0lU
https://youtu.be/uXGAj1e3SdE
https://youtu.be/EaZLslf3cv0
https://www.youtube.com/watch?v=972QCEahPNg
https://www.youtube.com/watch?v=fehIrjdPMbs
Not all of this is Americana, Shirley Collins is british but her early stuff is amazing. Linda Perhacs is worth a listen as well. Have a look at some of the Alan Lomax archieves as well
Listen to some Hank Williams
The Band is good cracker-core.
https://www.youtube.com/watch?v=Tqd_uTCWzqw
Give George Crumb's American Songbook a try.