[SeanLuke]

In Italy they still fondly remember a TV host whose (real, not stage) name was Mike Bongiorno. Buon giorno ("good day") is a standard salutation like good morning. He was Mike. an utterly US name, because he was born in New York.

[vanderZwan]

Is Bongiorno a common last name in Italy, or is it also a product of his ancestors migrating to the US?

How last names can change is fascinating to me. I have cousins who would have had the same last name as my (Chinese) grandfather, except for the fact that that my grandfather emigrated from Indonesia to the Netherlands before it became independent, and their branch of the family did so afterwards. Meaning Indonesia forced them to change their last names.

[retrac]

Bongiorno is a regional (Venetian?) or historical spelling; it may be less common in Italy than outside of Italy these days. Wikipedia lists most of the prominent living people with the name as being in Australia, the USA, or Argentina, though there's a few Italians. Buongiorno (the current Italian spelling, extra "u") is a common enough Italian last name.