Johanna was not married when Joseph was born. In these cases very often the father is not named. MAYBE it is the man she married later, Sauer.
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New York, Passenger Arrival Lists (Ellis Island), 1892-1924 listed
Josef Ratsel 30y from Hohenau arr: 20.4.1911
more siblings of John?
Hattie Retzl * 13.9.1914 Bettendorf, Scott, Iowa f: Joe Retzl, m: Frances Retzl.
Wilma Retzl, * appr 1913 Scott, Iowa. f: Joseph Retzl (Austria) m: Fannie Retzl (Czech.), brother: Hans 8y (Austria)
Joseph´s mother Johanna married a man called Sauer.
? John F.W. Sauer (birth Austria) oo 11.11.1915 in Augusta, Des Moines, Iowa Fannie M. Schirmer.
father: John Sauer, mother: Johanna Raetzel
? John Sauer + 2.5.1969 in Santa Barbara *10.6.1890 in Austria. mother: Retzel