I can definitely say I am an American. I'm also Irish, German, and a bit of Polish because of my family's ancestry.
But for smaller categories, I honestly am not sure where I fit in. Sometimes I say I'm a Pennsylvanian. Other times I feel more like a New Yorker even though technically I was not born there. The reason for this is that my family came from New York. My ancestors chose to live in New York when they migrated to the United States from other countries - to be more specific, they chose to live in Long Island. They just stayed there for generations. My father was born and raised on Long Island. My mother's from NJ, but I think she was born in NY as well. She did eventually move to LI during her college years though. Then I was conceived on Long Island as well, shortly after my parents married. The reason why I wasn't born there was because my parents decided to move to PA while my mom was pregnant with me. So basically I have a big part of NY in me, and I do fit some characteristics of a New Yorker. Yet I was born and raised in PA instead. That's why I get confused about which state I should identify with sometimes.
As for general regions, I do identify with being a 'Northerner.' Occasionally I'll call myself a Yankee as well.