I have lived in Ireland all my life, but my Mother's family are from Wisconsin.
Forgetting for a moment about the differences in food stuffs and preparation methods, the one big thing that always strikes me when I visit my US family is the total reliance on their car for everything. Here, if I want to go to the shop up the road, I walk there. Kids walk to school. We walk to church. And 'going for a walk' is something people do for fun - it is not unusual.
When my cousin stayed with me for a summer a few years ago, the first time I told her that I was going for a walk, she really didn't understand why I was doing it! She kept asking me where I was going, and what was I going to do when I got there. The concept of going out, walking round the town and local countryside and then coming home again, was totally alien to her. But, by the end of the summer she was a convert and was 'going for a walk' every morning.
So, Americans, you need to get out of you cars more, and walk places!