I spent some time in France and the UK, a few years ago. One of the things, that amazed me was how the locals knew me and my ex were "Merkins". We'd walk in, not open our mouths; yet, they addressed us as being from the US. We weren't wearing flags or stuff like that. I don't know if we had on big signs ,which said, "AMERICAN TOURIST" or what. I guess in a strange way, this was an assumption on their part. I don't know what it was, but an awful lot of Europeans could pick up that we were Americans,, without us saying a word.