A: Philadelphia, Pennsylvania, United States
Dewey Urges Standardization of Library Catalogue Cards
The subject catalogue ("Schlagwortkatalog") of the University Library of Graz. The card shown refers to a text by Hans Schleimer who made up the rules for this catalogue.
In 1877 the American Library Association, headquartered in Philadelphia, urged on by Melvil Dewey, standardized the size of library catalogue cards. At this time most libraries maintained their main catalogue in book form.