I haven't found people unfriendly to Americans, but I have seen some really rude Americans. I can get by in French speaking places.
My travel has been mostly
North America (Canada, Mexico, Belize),
Caribbean (Bahamas, Aruba, St Lucia),
Europe (Ireland, England, France, Germany, Netherlands, Switzerland, Austria, Hungary, Spain, Monaco). Last 2 very briefly, we drove from southern France to Barcelona to fly home, visited Parc Guell.
DH has been to many more places in his scuba trips!