checking ancestors names any idea where these may come from :Phineas / Cushmere?

https://familysearch.org/search

(free)

has 17 people named Cushmere, with that exact spelling. One may be your great grandfather. They seem to come from England, France, and Indiana.

Phineas is a male given name of Greek origin. But it has always been used extremely rarely in post-Classical times, and as a surname in modern English-speaking countries is more likely to be an anglicisation of a foreign surname of quite different origins.

Cushmere *sounds* as though it ought to be an English-language locational name ('mere' is an old English word for a pond or lake) but it isn't. My guess is that it is a non-English-language name anglicised in the USA so as to sound not-foreign.

Stop checking names, name are words they come from language, NOT countries so it will not help you find your ancestors at all