Linda Morzillo writes
<< I don't think that one had to be a citizen to obtain a Social Security
number in 1940. My grandfather applied for his on 1936 and he did not
become a citizen until 1945. >>
Similarly, my father obtained his Social Security card the year we
arrived in the US, 1941, though he did not become a citizen until 1948.
Searching HOLSTEIN or SPEIER-HOLSTEIN (Neuenbrunslar, Gensungen)
KAHN (Alsace, Belgium), SCHIFFRES/SHIFRES/SZYFRES (Grodno), HALPERN/GALPERN