I have no idea how Americans behave overseas. The ugly American abroad stereotype exists but honestly I always assumed that Americans visiting abroad were less likely to be loud and obnoxious than the average American who never leaves the country.
There are people who live abroad, and people who are just tourists. When outside of one's own culture, the foreign residents /tend/ to be more interested in fitting in, making accommodations, and generally not assuming that their own culture is "correct" and the one they're experiencing is "weird" or "wrong."
Tourists are usually more interested in briefly experiencing something other than daily life, but as an amusement.
The rudest tourists I encountered in the USA were French. In Japan, the Chinese have been stunningly oblivious to even the most basic consideration of others.
The loudest talker on my team is a French Canadian who is bad at apologizing. It's possible he's not Canadian…?