Having just read that John Beaumont developed the Blackhouse Colliery at Ayr from 1770 and brought in some miners from Newcastle on Tyne I started wondering whether my ancestor's had actually come back to Ayr from Newcastle.

Newcastle has a lot of people of Scots ancestry and many Presbyterian churches.

Despite a thorough search of all the Presbyterian Churches of all varieties I was unable to locate more than "three Coldwalls" over the entire range of parish records listed.

http://freepages.genealogy.rootsweb.com/~hughwallis/index.htm

Obviously the Caldwell family did not figure large in the population of that area.

If they had been a more East-Scotland or North-English family I might have expected more evidence of a migration to Northumbria.

There are many Caldwell's located in the Lothian's in the IGI and these are more obviously offshoots of the original South-Western family. Apparently the migrations did not extend to the coalmining-industrial conurbation of Newcastle.

On the other hand there are many Caldwell's in Lancashire and this is more likely the route taken by economic migrants from the South-West of Scotland and also back from Ireland.

Tom