The Standard Industrial Classification (SIC) code system was born in the 1930s and used for several decades. It was developed by the Interdepartmental Committee on Industrial Statistics, established by the Central Statistical Board of the United States who developed the List of Industries for Manufacturing, published in 1938, and the 1939 List of Industries for non-manufacturing industries, which became the first Standard Industrial Classification for the United States. The SIC system was last revised in 1987 and was used by most government agencies including the Census Bureau and many private publishers. It was last used by the Census for the 1992 Economic Census, though many databases still include it as part of their indexing. In some cases, particularly when it comes to retail, using SIC codes can be better than using NAICS codes.

The system is broken down into 10 Divisions (A-J) and each is then divided into Major Groups (2 digits) and then into specific 4 digit numbers. Here is a chart of the division structure:

If you are doing historical research you will need to understand and use these codes so we have also included the records for the previous editions of the SIC manuals.