Here's my name change story:
We arrived in the US in NYC on January 20, 1951, under the Displaced Persons Act. "We" means my mother and my two maternal grandparents, my Mom's younger brother Joe, and me. My biological father had died of food poisoning in September 1949, in Frankfurt, a few months before I was born. I was born in Amberg, in the American Zone of Occupation, and my family had been in Germany since 1946, having lived at DP camps at Hof-Saale, Degendorf, Regensberg, and finally in Amberg.
We arrived aboard the troop ship General C.H. Muir. I caught measles on board, so Mom and I were quarantined for 10 days at Ellis Island, while the rest of the family disembarked normally at the West Side piers in NYC. HIAS housed and fed us for a few weeks in NYC, and then sent us by train to Baltimore, where our sponsor, Mom's Uncle Leo and his family, were waiting for us.
Anyway, on to the name change: Even as a young child, I heard the name Przedborksi, and somehow knew that it used to be my grandparents' surname, which was now Preston. So I asked my Mom what happened, and she said "the man at Ellis Island changed it." So that was enough to satisfy a 7-year-old, and I didn't think about it for years.
Then, in my late 30's, at some family gathering, I related the story to a friend or relative, and Mom, overhearing me, said, "That's not what happened! I changed it."
So the real story is that we arrived in the US as Przedborski, and Mom, wanting to be a American, knew that this was not a "good American name." She picked up the Baltimore telephone book and looked for names starting with P-R-E (forget the "z", she said!) and once her eyes fixed on "Preston," she knew she had found her new name. So she went to court and had our name legally changed to Preston within the first few months of residing in America.
In the late 50's, my Uncle Joe (my de facto big brother, just 5 years older than me,) and I used to watch "Sergeant Preston of the Yukon" on our enormous Philco tv with the diminutive screen, and we thought we were somehow related to the heroic title character.