When did the father of George J. Gruen pass away ?
Dietrich Gruen Dietrich Gruen (February 22, 1847April 10, 1911), was a German born watchmaker who emigrated to the United States in the 1860s and later founded the Gruen watch Company.
Tobias Dantzig Tobias Dantzig ( ; February 19, 1884 – August 9, 1956) was a mathematician of Baltic German and Russian American heritage, the father of George Dantzig, and the author of "" (1930) and "Aspects of Science" (New York, Macmillan, 1937).