I am descended from Johann Willmert (b.9 JAN 1839) and his wife Henbrietta Hubner (b. 5 OCT 1837). They arrived in the USA In Jun 1881 and moved to Milwaukee, WI. They brought with them their children Wilhelmine, Antonio, and Gustav (my gr grandfather).
My grandfather mentioned surnames Priebe and Brandenberg in relation to this family which he visited on trips to Iowa, but I have not been able to connect them.
Johann Willmert may have had a brother Carl August Willmert who lived in Milwaukee during the same period.