Howdy,
The wafted to the skies verse is one that Arlo Guthrie has recorded on different albums. Since he often talks his waythrough this and many other songs with explanations about them, I believe I remember him saying that this is his favorite verse to the song, and that it was added by Lee Hays. I'll check out one of the Pete Seeger and Arlo Guthrie together albums and let you know if I find any different explanation.
Allinkausay,
Bill