Plenty of tunes used in morris dancing have also been found in vernacular tradition in the USA (some, of course, having originated there); but used for purposes other than morris dancing, which is a Revival phenomenon in that country.

That isn't to say that morris dancing didn't take place in what is now the USA at any time between the beginning of colonisation and the 20th century Revival; just that if it did nobody seems to know about it (this isn't my subject, though, and others may be able to point to historical records that would contradict that) and it didn't survive as a tradition. Specialised community traditions tend not to travel with migrants unless a significant number of members of that community migrate, and settle, together. 'Ebor's' comments are relevant too, though they relate mainly to the early phases of migration.

I doubt if there are many tunes (if any) that are associated uniquely with morris dancing anyway. Making a list of tunes that happen to have been used in the morris tradition that have also been found in America would result in a list of mostly well-known tunes that have been used for social dancing and/or songs in Britain as well. What does that achieve? I don't really see the point of the question.