John, In the 18th century most of the better off in Britain were into theatrical and pleasure garden songs and songs we wouldn't really recognise as folksong nowadays. The Jefferson books are really of this type. Culture in America at that time more or less, as you would expect, mirrored that in Britain. Whilst possibly in the 16th and 17th centuries there was some interest in the ballads, by the 18th century they were the province of antiquarians and those much further down the social scale. What survived by then was more the province of old nurses and the poorer tradespeople, those who couldn't afford to buy the current sheet music and go to the theatre. This is one reason why the likes of Dibdin's prolific output didn't survive in oral tradition, and of course the nature of the material. If you trawl through 18thc collections you have to put up with 99% flowery poetic mush before you come across the 1% that looks remotely like folksong, but they are there and it is worthwhile if you have the patience.