Here's the last original Carter Family titles:

When I'm Gone;
When Silver Threads Are Gold Again;
When This Evening Sun Goes Down;
When the Roses Bloom in Dixieland;
When the Roses Come Again;
When the Springtime Comes Again;
When the World's on Fire;
Where Shall I Be?;
Where the Silvery Colorado Winds Its Way;
Where We'll Never Grow Old;
Who's That Knocking on My Window;
Why Do You Cry, Little Darling;
Why There's a Tear in My Eye;
Wildwood Flower;
Will My Mother Know Me There?;
Will the Roses Bloom in Heaven;
Will You Miss Me When I'm Gone?;
Winding Stream;
Wonderful City;
Worried Man Blues;
You Are My Flower;
You Better Let That Liar Alone;
You Denied Your Love;
You Tied a Love Knot in My Heart;
You're Nothing More to Me;
You've Been a Friend to Me;
You've Been Fooling Me, Baby;
Your Mother Still Prays (For You, Jack);
You're Gonna Be Sorry You Let Me Down;
You've Got to Righten That Wrong;
Young Freda Bolt

What's interesting to me is that some of the Carter's most famous songs like the Circle Be Unbroken; Wildwood Flower, Worried Man Blues
are freely used even though the arrangements by the Carters are unique and what we sing-publish etc are based directly on them.

Yes they are based on other songs but you could say that about 90% of their songs. Yet their arrangements are basically standard use for the songs and no one questions copyright infringement.

On their lesser known arrangements to quote the Artful Codger above:

"However, a caveat:
Unless you enjoy litigation, bear in mind that the Carters altered many of the songs they sang not only to fit their particular style, but expressly to make their arrangements copyrightable--they were urged to do this by Ralph Peer, their agent/manager. Granted, A.P.'s copyrights often infringed on the copyrights of others, whether intentionally or not; that is now immaterial. In preparing a song, the Carters frequently changed melody lines, chord progressions and lyrics; these changes are identifiable enough that a court might easily detect the Carters' still-copyrighted contributions in your arrangements, unless you derived directly from original or p.d. materials."

This to me is the confusing part, where did the verses for "Circle Be Unbroken" come from: The Carter Family. Did they write them? We don't know. Is their copyright valid?----NO