Gaelic speaking Indians in colonial America, no lie.

http://en.wikipedia.org/wiki/Madoc

I met a red headed Indian young man among the creoles in Gainesville, Florida, who was a horse whisperer. Red wavy hair, freckles, light skinned, looked Irish, but 100% Indian.

Also, where I grew up in Southern New Jersey on the Delaware Bay, we have a unique gaelic accent down from the early Welsh settlers, with an island in the nearby Chesapeake Bay, Smith Island, where they used to have a gaelic accent so thick even I couldn't understand them. Unfortunately, tourism and the internet decimated this micro culture of fisherfolk.

Can't seem to find many linguistic studies on this, but it might be worth a look.