Surname FONDA (first mentioned in year 1230 - Dominicus FONDA the prominent of Piran) has an Italian roots and originate from the town Piran. Most of its history Piran depended to Venetian Republic. Today is a part of Slovenia. It seems, that Piran is the only center from all FONDA's originate.
There are many inaccurates about Fonda surname origin appears in this forum:
1. FONDA isn't a noble family and never have been. It's talk, that a source to which Rev.Williams,1916 refered ("Roland's Rietstap ...") include Coat of Arms made by orders around year 1900. All story about this is ... only story.
Maybe, the only valid FONDA Coat of Arm depend to a bishop of Trogir Hieronymus FONDA, who lived in 18.century.
2. It's believe that surname FONDA got its end form in the 12.century furthest in Piran. It depended to an Old Roman (plebeian !!) Clan called FUNDANIUS -> FUNDANI. This clan settled in an area south to Rome (today Lazio) already in the begining of Roman Republic (6.century b.c.).
3. Dutch FONDA origin is regular only for an American branch.
I don't know much about American FONDA branch (Dutch Ancestors). I believe that this branch history is clear.
More about FONDA surname origin you can see at Web site bottom: http://www.amadej.si/users/fonda/Moj_Rodovnik/fonda.htm
Unfortunately, it's only in Slovenian, but there are many statistical data which should be understand without of language knowledge.