Lotsberg

Hello I have just started working on my wife genealogy and was trying to find the ship that they arrived on in the US. It is my understanding that when they arrived in the US instead of writing their full name the clerk said thats lots of bergs and thats where the name come from. I do have a place and a year of birth for the immigrants would any one be able to direct me to where I would be able to find out their real(traditional) last name.