were Any ones 16 great great grandparents all born in the same country? If so which country?

 Most folk's never meet their great(×2) parent's @ all zxq

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My Scottish relatives on my father's side go back forever on MacFarlane, - Campbell, - Graham, right up to Alexander Stewart, Bishop of Moray and Sinclair family lines. So yes it's possible.

My mother's line is much more complicated to do, because her name isn't as common as my father's last name. My mother's line lived in multiple countries. And they're Gypsy/Roma travellers. 

So the more common the name the more documents there will be available. 

Lastly just looking at my mother and father's information above makes me feel as if I'm a strange mix of everything.   

I have researched 8 lines of my family and 3 of them date to the 15th and 16th Century in the US.  There is no way to answer as the people here do not have access to ALL verified research that has been done.

I have researched my records 12 generations back here in the USA. That's pretty close.

Yes all born in England UK

Yes.  Several of my ancestors going back many generations were all born in England, which is where I live now.

Yes. What is now the US of A.