[2] Kempner was a native of New York City and graduated from Columbia College, Phi Beta Kappa, in 1919.
[3] He was a managing executive of Heidelbach, Ickelheimer & Co. from 1920 to 1927 and a partner of the firm until 1942 along with Stern, Kempner & Company and Spencer B.
[2] He served a lieutenant colonel in the United States Army's finance department during World War II and headed the Victory Loan program for the Federal Reserve Bank in San Francisco, where he remained for the rest of his life.
[8] A civic leader, he was also a founder of French American International School in San Francisco.
[3][12] He died on August 1, 1987, at age 88 in San Francisco, survived by his second wife, Charlotte Kempner, two daughters, and four grandchildren.