Student American Business Institute, 1914-1915, City College of New York, evenings, 1919-1920.
Associate editorial and accounting departments New York Times, 1915-1918. Founder South. Grossman Company, New York City, 1921. Auditor Fox Film Company, 1922-1923.
President Grossman Stamp Company, Incorporated, New York York City, since 1927.
Founder Longacre Public Company, 1957, Hygrade Sports Card Company, 1984.
Member American Philatelic Association, American Stamp Dealer"s Association (president 1966-1967, director), King County Grand Jurors Association, American Topical Association, Royal Canada Philatelic Association, American Numismatic Association, Association Stamp Exhibitions, Grand Street Boys Association, International Federation Stamp Dealers Associations, Judaica History Philatelic Society.
Married Doris Boxer, August 21, 1932. Children– Judith, Lucille, Lawrence.