When did the father of George J. Gruen pass away ?
George J. Gruen George J. Gruen (1877–1953) was an American watchmaker who managed the Gruen Watch Co. He was the second son of the founder Dietrich Gruen.
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).