Hello Mildred and Sue,
I'll write in English, might be quicker.
I found the marriage record index of Gustin FINGADO and Barbara SCHAAF, oo 16 May 1883, Manhattan, New York.
His and her age dont correspond to ulterior Census data. Their parents are given as
Fred W. FINGADO (apparently Friedrich Wilhelm?) and Mary MARSH (perhaps MARSCH?)
Barbaras parents are Michael SCHAAF and Mary E. HART.
Barbara is on Geneanet.org Barbara Schaaf : Genealogie durch Hans BRUNS (hbruns) - Geneanet
as Barbara SCHAAF *10 Jan 1861 Leimersheim/Palatinate, parents Michael SCHAAF and Maria Elisabeth SCHARDT.
You probably know this already, and also her sister who married an American?
There are lots of August, Gustav, Adolph and Wilhelm FINGADOs in and around Lahr/Baden and some more in Alsace.
Was he protestant or catholic?
Your g-g-mother BENNEWITZ wasn't August Adolph's mother, was she? Where does she fit into the tree? After all you have 4 g-g-mothers!
I would like to help, please write to colette.llorca@orange.fr
Regards from France
Colette (Llorca)
www.llorcahome.org