Scottish? Irish?
Scots-Irish?

Within sight of each other on a clear day, Scotland and Ireland are also close in  heritage, culture and ancestry through a common Celtic history. Scotland is actually named after an ancient Irish tribe, the "Scotti" of Dalriada who migrated to Scotland beginning circa 400AD.

Surname spellings create confusion as to national origin. For instance, a common myth is a name’s “Mc” prefix or patronymic suggests the origin was Irish while “Mac” is Scottish, neither reflecting national origin.

Lowland Scots would also migrate to Ireland to become the Ulster Scots, later the Scots-Irish. Those who migrated to the American Colonies would become the second largest European immigrant group before the American Revolution.

See a page with information on how to initiate researching one's ancestry. And a page with a listing of Scottish clan branches in the Upper Midwest.