Clearly the belief that names were changed at "Ellis Island" is a myth -
the U.S. Government passenger arrival records (found via the Ellis
Island web site for example) were completed on the "rag ships" en route
to America, not after arrival.
Many immigrants, such as my grand parents, came over on German ships,
often out of Hamburg. The German crews completed the forms at sea.
Consider the scenario - a long line of Eastern European immigrants who
speak Hebrew plus Polish or Russian or whatever. A very busy German
clerk says "namen?", my grandmother says "Birger" - the crew member
hears "Berger", writes it down and the name has been "changed."
Consider all the possible opportunities for error with your name.
Mike Berger