This might also be of interest to you:
http://search.ancestry.co.uk/cgi-bin...&uidh=000&cp=0
It seems to be an almost exclusivly American name and is listed in the Dictionary of American Family Names (OUP).
http://www.ancestry.co.uk/name-origi...ame=hergesheim
Hergeshumfr is an alternate spelling.
If I were to take a guess I would say that it was a name taken by 19th C immigrants to the US from Hargesheim, as there seem to be a few references from 1900 but little after I would guess that some people dropped the name in WW1 and WW2 as being to German (allot of people changed there name at that time due to ill feeling against Germans)