I worked on a summer camp in the USA in the 1980s. We had a day off and went into the small local town (Kent, Connecticut IIRC). A small group of us British students went into the local bar for a beer before we went back to camp. The barman/owner was quite slow about giving us the bill for the beer. This is going to be expensive, we thought. But he just said 'It's on the house. Tell people Americans are nice when you get home'. It was a small kindness, but greatly appreciated by some poor students.