S.O.S. on source

[L Verge]

Kauffman uses the quote in American Brutus, but his source notes merely say that Frederick Stone later told George Alfred Townsend that Herold was with Booth the night of April 11. Kauffman also cites John Clampitt as having Powell with Booth. One would have to conclude that the quote went down in history thanks to Herold and/or Powell -- or unfortunately, through the literary license that George Alfred Townsend may have taken when he later included it in Katy of Catoctin.