My great-grandparents all came from Germany, but I must confess that I don't feel a lot of connection with it - I do respect Germany and its people, but I haven't experienced it directly and so I don't really know what it's like to be German. I've never even been there, although my dad has - he was stationed there in the Army Medical Corps (in fact I was almost born there, he and my mom came back to the US right before).
I am, OTOH, very proud to be American. Why shouldn't I be? My country isn't perfect, of course, and I'd never claim that it was. But I grew up here, and I don't feel in any way ashamed to be an American. Whatever questionable things my country has done, I'm not responsible for them, nor can I be made to feel so. America has done some bad things, but also some good things. I choose to concentrate on the good. What's wrong with that?
I mean, I'm not ignoring the bad parts about my country's history. I do want to learn from them. But I choose to try and make things better from within, as it were. I don't want to destroy the system - I want to BE the system. Just make it better.