Aghhhhh! Left out the most important part from SingOut!:
"Addendum (Fall 1992) & Clarification
"The two paragraphs ... [quoted in my last post] appear as they did in the original "Reprints from Sing Out!--Volume 8."
"Some of the descriptive information which appears in those paragraphs has been found to be inaccurate. "How Can I Keep From Singing" does not derive from North Carolina Quakers. The original words and music (i.e., the first verse at the left and the 2nd and 3rd verses as they appear in "Sankey") were composed by Anne Warner and Rev. R. Lowry, and published in 1864. The third verse (which begins with the words "When Tyrants Tremble," and is included above) was composed by Doris Plenn about her friends imprisoned during the McCarthy era."
Emphasis above is mine. This material, and my last post, are transcribed from The Collected Reprints From Sing Out!, Volumes 7-12, 1964-1973, ISBN 1-881322-00-9, published in 1992.