This remark by John Robinson made a few days ago slipped by without comment:

I find it hard to find 'English' folk songs, but perhaps that's just me. After a bit of digging I often discover that whatever shiny new/old song I've learned was originally Scottish, collected by Francis J Child...

John, you need to remember that Child's sources were overwhelmingly Scottish, and there's far less evidence about what people in England were singing around 1800 than there is for Scotland, simply because nobody much was collecting it. Even so (and acknowledging that ballads like 'Tifty's Annie', 'The Battle of Otterburn' and 'Sir Patrick Spens' did originate in Scotland), a lot of the ballads most popular in tradition most probably originated in England. The notes to the songs in Roud and Bishop's 'New Penguin Book' make this pretty clear.