I don't know how House Sparrows originally arrived in America, whether they were deliberatly introduced or did the sparrows hitch a ride with the early settlers, who knows. I was thinking is there any difference today after a few centuries of separation from their European ancestors. I realize that sparrow immigration didn't just stop in the 1600's and that there's been enough transatlantic shipping since then for a few to stow away and reach land. How much of a difference that would make to refresh the House Sparrow gene pool I have no idea. Do they still look the same I wonder?
