The distinguished surname Kogan is a proud sign of an ancient Jewish culture. The surname Kogan is an occupational surname for a priest, and it comes from the Hebrew word kohen. Traditionally, priests were considered to have been members of a hereditary caste, descended from Aaron, the brother of Moses. Not all Jewish bearers of the surname Kogan belong to this caste, however. When many Jews were being forced to join the Russian Army for a term of 25 years, a number of them changed their last name to Kogan, because members of the clergy were exempt from service.
^ Filby, P. William, Meyer, Mary K., Passenger and immigration lists index : a guide to published arrival records of about 500,000 passengers who came to the United States and Canada in the seventeenth, eighteenth, and nineteenth centuries. 1982-1985 Cumulated Supplements in Four Volumes Detroit, Mich. : Gale Research Co., 1985, Print (ISBN 0-8103-1795-8)