About 1970, The English Folk Dance & Song Society came out with a series of books with songs from the Hammond & Gardiner manuscripts. I noticed that there were a lot of Irish songs in them: Marrow Bones, The Wonton Seed, The Constant Lovers and The Foggy Dew.

A explanation (which I recall was made somewhere in one of the books) is that many of the hawkers of broadsides were Irish. Maybe they were Famine refugees. In addition the Great Famine (1847 - 1853), there were a number of other famines in the 19th century.

All the best,
Dan Milner