The Druids, from what little I know were in Southwestern England though there is evidence of them all over, but they were centered around what is now Glastonbury I think. In my tree, the patriarch John Bligh is from Cornwall, c1600 which would fit the Druid background. Something I never thought about until you brought it up.
Here's Wikipedia on those people:
"The Cornish (Cornish: Kernowyon) are a people associated with Cornwall in the southwest of England, in the United Kingdom. Some have argued that the Cornish represent a distinct ethnic group within the UK, which can trace its roots to the ancient Britons who inhabited southern and central Great Britain prior to the Roman conquest, and some in the county today continue to assert a distinct identity, separately or in addition to English or British identities." I believe Britons identified themselves with the Druids, though not as ancient.
I have no evidence of this but the founding of Rhode Island on religious freedom and the growth of Quakers there (absolute equality, worship outdoors, no paid ministers or church buildings, etc) could be another possible clue to Druid background in some of these people.