Dolly wrote and sang a heart-breaking original version. her good friend Linda Ronstadt recorded an even more soul-wrenching version, with pain seeping out of the speakers as she sings. Whitney Houston, who confuses emotion with volume, technique with feeling, and sings about loss as though it's a case of the mumps has also recorded a version, which outsold the others by millions. There's just no accounting for taste, or indeed the absence of it.
I think jenstar is correct - Dolly has been married to her husband Carl for thirty years, although he is a shy man and stays firmly out of the spotlight. Porter Wagoner's TV show gave Dolly her break into stardom, and the couple enjoyed a very close working and personal relatiionship, although they maintain it was platonic. When a career split occured, bad bood between them was exacerbated by Wagoner taking legal action for alleged unfulfilled contractual obligations, but Dolly has maintained a close affection for her early mentor, resulting in this famous song.