Gerhard's answer assumes that the person in question did indeed come

from Germany and was called GELLERMANN before emigrating.

Now, if the person was actually named SCHMIDT, we'd have nowhere to
turn. But some variants should be considered, notably KELLERMANN.

Also, note that many immigrants listed "Germany" instead of eastern
European locations as their origin, and a few listed the place where
they embarked. (Supposedly the vast numbers of Irish -Americans "from"
County Cork include many who literally "came from" there.)

And if "Germany" was a slight westward adjustment of the facts, then the
surnames GELLERMAN, HELLERMAN and KELLERMAN >from Poland or the Pale of
Settlement are a distinct possibility.

Do you know whether the place where this person lived in Nebraska was a
German-speaking community? Was there a Jewish community nearby?

As Gerhard points out, there's nothing about the surname itself that
would point to Jewish origins in Germany. In eastern Europe, on the
other hand, the probability of such a name indicating Jewish origins
would be a little higher.

Roger Lustig Princeton, NJ USA Research coordinator, GerSIG

On 3/22/2013 11:16 AM, Gerhard Buck wrote:

Lars Menk does not have the surname GELLERMANN (nor variations of it)
in his "Dictionary of German-Jewish Surnames".

The name means that its first bearer came >from Geldern, a German city
between the Lower Rhine and the German-Dutch border. By assimilition
of the letters l and d Geldermann became Gellerman. The name may also
refer to the Dutch province of Gelderland. Originally the name could
mainly be found in the Rhineland near the Netherlands. (Source: Hans
Bahlow, Deutsches Namenslexikon. 1967)

If you want to see, where this or any other German surname can be
found in Germany nowadays, go to the website of the local (= oertlich)
telephone directory: www.dasoertliche.de <http://www.dasoertliche.de>
and enter the family name on top of the first page. A map will show
you all the places, where persons with this name live.