Dating in the vicinity
However, it did not start using this code until 1964.(I have not been able to find date codes on maps issued by Diversified in 1962 or 63).Clason Map Company was a map publisher in Denver, Colorado that published the first road atlas of the U. Use the link above to connect to a site at Michigan State University to learn more about dating Clason maps.The following information was provided by Jim Wakefield: Some, but not all, Diversified maps contianed a three or four digit date code.Arrow Map Incorporated Automobile Club of Southern California Buddhist Calendar Dates California State Automobile Association Clason Road Maps Diversified Maps General Drafting Company George F.Cram Company Geographers A-Z Map Company Geographia H. Gousha Company Hagstrom Map Company Midwest Map Company National Automobile Club (San Francisco) Novo Print USA, Inc.
The second to last digit (which, in my experience, is always a 1 or a 2) appears to stand for a first or a second edition of the year of issue.
The following list gives the two-letter date code, the year it indicates, and an OCLC number for a record input by the Library of Congress.
Occasionally the map code on a given map doesn't agree with its publication date, but this is usually a case of a reprint.
After that, the two-letter code became more complex.
It started of logically enough, with AB and AC, then became quite irregular in pattern, for reasons known only to whoever assigned these codes.