We learn in the beginning of the saga that the family's original last name was Andolini from Corleone ,Sicily. What always confused me was the change in last name after Vito migrated to America ? It appears to me that the immigration board changed it and mistankingly thought his last name was Corleone.

It was an immigration official who mistook another immigration official's stating Vito's hometown for his last name.

There were lots of mistakes like that made by Ellis Island officials. I have a friend whose last name is spelled with one T, but his relatives in Ireland spell it with two. His grandfather always said that one T was lost in Ellis Island.

My grandfather had a polysyllabic last name. The immigration official didn't want to bother with all the syllables, so he assigned him the first one. That's why it's easy for me to sign my name.

I knew a guy named Rocco Separato. When his grandfather immigrated the officer asked him where his wife was. The man said in Italian tha he and his wife were separated, and thts how he got the name.

That's one of the funniest things ever I've read on this board.

I understand this is pure speculation but had Vito's name not been changed at Ellis Island, would he have still been in danger from Don Ciccio?

My opinion is that he would've been okay, as Ciccio's influence could not have extended that far. Any silimar/opposing viewpoints, and is there any evidence I am overlooking to back up either side of the argument?

As you said, Ciccio's influence didn't extend into America because if it did, he'd have had ways to find young Vito no matter what his last name was. And, "Corleone" would have been a major tipoff--that's where Vito came from and that's the town Ciccio ruled.