Just to clarify: Amby Thomas was talking specifically about When First I Came to Caledonia, which contains the "pen from Pennsylvania" verse. When I first read his comments, I thought the other song When...Caledonia was "mixed up with" must be either Peggy Gordon or some other with some of the the same floating verses. Looking at his words now, I realize he was referring to the Gaelic song the melody and chorus of which are incorporated into When...Caledonia.