Could I actually (also) be Ukrainian?
Dude, theoretically:
A Mexican circa 1839 becomes an American citizens, his children move to California or where have you, they intermarry and so on. Fast forward to 1940 some or other of his progeny moves to well...say to France. Fast forward to 2018, one of his grandchildren post on an American forums, hmm has anyone heard the surname Gonzalez, this surname sounds a bit unusual, I'm wondering if it is actually American.
What would you tell him?
It depend on what you are looking for.
Poland used to be an empire not unlike the US for about 400 years spanning half of the continent and many religions, creeds, races and ethnicities.
Take your pick.