They had two children :
Joseph DONISCHAL born 03/30/1890 and Louise born 05/14/1891 in PFASTATT, and left their children in Alsace behind them.
We found these ancesters on the German Immigration lists , because at that time, their bithplace , in the region Alsace used to be German, and belongs to France nowadays.
We could not find any trace of them in the USA with these names afterwards, and can assume that they perhaps decided to change names.
Joseph DONISCHAL is my grand father.
My uncle has been able to trace all our genealogic links since then, using French archives.
Thanks in advance for your help!