Just a small additional note to Dicho's first message re: spreading these through the English-speaking world ...

They also spread into other languages. There are several minstrel songs which have been absorbed to varying degrees into the Welsh language repetoire. (Tell-tale signs include references to Jim Crow and exotic wildlife - like the whipoorwil.) One, "Moliannwn", is so popular it's achieved 'anthem' status in Welsh-speaking Wales.

sian