just said this to someone else and that is I have a manchester English accent and having been to the mountains I can honestly say that many words and how they are said are very much alike.
When I went up north it was just so differently but I suppose it was because the English, scots irish etc moved south when the mass immigrations happened into the north east
The North West of England was subject to a lot of immigration from Ireland, especially after the 1840s when many poor, desperate Irish people flooded into Lancashire to escape the famine and look for work in the cotton mills. When I was doing some work for my history degree dissertation I found out that about 10% -15% of the population of Manchester was Irish-Born (not including those born in England but of Irish descent) and this figure was even higher for Liverpool, at 18%-20% (again, not including their children born in England).
I suspect the similarity in accents and pronunciation in the Northwest of England and the Appalachians etc stems from a common Irish cultural influence, rather than emigration from the North West of England into the Appalachians...