His brother was Hans Zinsser, the celebrated bacteriologist at Columbia and Harvard who became best known for authoring the best-selling book Rats, Lice and History in 1935.
[2] In 1897 he established Zinsser & Company, Inc., whose president and chief chemist he was, and enter the emerging field of synthetic organic chemicals.
(The son John attended Harvard University, and was a chemist and associated with his father for some years, then later became vice chairman of the board of Merck & Co. of Rahway, New Jersey and president of Sharp & Dohme Inc. of Philadelphia and was on the board of directors of the investment bank JP Morgan in New York during the 1940s.
"Peggy" married Lewis Williams Douglas, scion of one of the most powerful families in Arizona and sole heir of the Phelps Dodge copper mining fortune, who succeeded Harriman as ambassador to London.
Ellen married John J. McCloy, the chief lawyer for the Rockefeller and the "Seven Sisters" interests, member of the Warren Commission, and advisor to nine US presidents.