By LOIS MAI CHAN
In the summer of 1898, the results of a project that was to have great impact on libraries in the United States and around the world for the next century quietly unfolded in the Catalog Division of the Library of Congress.
This was the advent of the new Library of Congress dictionary catalog with the integration of alphabetically arranged author, title and subject entries. The alphabetical subject headings system, now known as Library of Congress Subject Headings, or LCSH, was originally intended as a subject cataloging tool for the Library's own use. It is now serving thousands of libraries around the world and has become the de facto standard for subject cataloging and indexing in circumstances far beyond those for which it was originally designed.
This now enormous structure began with a small step. After the Library moved from the Capitol to its new building in 1897, its officials faced the question of how the collection should be organized. Major decisions were to establish a new classification system and also to adopt the dictionary form for the main catalog. At that time, Charles A. Cutter's Rules for a Dictionary Catalog was in its third edition and the dictionary arrangement was well on its way to becoming the predominant catalog form in American libraries. The Library's move to such a catalog, along with its practice of distributing its printed cards, put the institution at the forefront of American cataloging policy and practice.
In 1909, J.C.M. Hanson, the first chief of the Cataloging Division, recounted the beginning of LCSH. Actual work on the new subject catalog began simultaneously with the printing of the first author cards in July 1898, as well as the compilation of an authority list of subject headings. After noting that the American Library Association (ALA) list of subject headings, which had been "calculated for small and medium-size libraries of a generally popular character," was chosen as a basis with the understanding that considerable modification and specialization would be needed, he continued:
As a first step preliminary to the real work of compilation, a number of copies of the List were accordingly provided, a number of blank leaves sufficient to treble the size of the original volume were added, and the copies thereupon bound in flexible leather. ... New subjects as they came up for discussion and decision were noted on slips and filed. If the subject had already been adopted by the ALA committee, i.e., had appeared as a regular printed heading on the List, a check mark was added to indicate regular adoption by the Library of Congress. (Hanson 1909)
Hanson also noted that many other catalogs, bibliographies, encyclopedias and dictionaries were also consulted. These included the Harvard list of subjects, the New South Wales subject index and Forescue's subject index.
From that modest beginning, LCSH, currently containing slightly less than a quarter-million terms, has become the most comprehensive general controlled vocabulary in this country, and possibly in the world. An important reason for the far-ranging use of LCSH is the fact that Library of Congress cataloging records have been available to other institutions throughout the 20th century. The Library made available its printed catalog cards for purchase by other libraries in 1902, and the service was well received. With the advent of the online age, use of LC cataloging information increased considerably when the Library began distributing its machine-readable cataloging (MARC) records electronically, initially through weekly tapes, then through bibliographic utilities that in turn subscribe to a regular MARC tape service. Since 1993, LC cataloging data and LCSH have also become accessible online through the Internet.
Almost from the beginning, the Library took responsibility for giving other libraries an account of its cataloging practices. Indeed, according to Hanson, one of the Library's reasons for adopting the dictionary catalog was "a desire to be in a position to cooperate with the largest possible number of American libraries. "And as use of LC printed cards increased, many libraries felt the need to have access to LC's subject headings list. The Library responded with Subject Headings Used in the Dictionary Catalogues of the Library of Congress, which first appeared over the years 1910 to 1914. There has been a continuing series of editions and supplements ever since (with a title change to Library of Congress Subject Headings for the eighth edition in 1975). The 10th (1986) edition of LCSH saw the completion of its conversion to machine-readable form, and the file is now available in a weekly tape distribution service, in combination with LC Classification on a CD-ROM called Classification Plus, through bibliographic utilities and, more recently, on the Internet. To further assist catalogers in the application of the system, the Library of Congress began publishing Subject Cataloging Manual: Subject Headings in 1984.
Currently, LCSH serves both internal and external needs. It continues to fulfill its original function as a tool for the Library's own use. But with increasing outside use of the system its role has grown. Within the United States, it is the most widely used subject access system in online library catalogs. A number of bibliographic utilities such as OCLC Online Computer Library Center and RLIN (Research Libraries Information Network) and commercial retrieval services such as WILSONLINE and DIALOG carry databases containing MARC records, providing their subscribers with subject access to library collections by means of LC subject headings. Many other commercial databases use controlled vocabularies adapted from LCSH for subject indexing.
Internationally, LCSH has also gained wide acceptance. In recent years, as libraries around the world seek to provide or improve subject access in their catalogs, many have implemented controlled vocabularies. Libraries that have adopted, translated or adapted controlled vocabularies based on LCSH include those in Belgium, Brazil, Canada, the Czech Republic, France, Great Britain, Lithuania, Malaysia and Portugal.
Throughout its history, LCSH has been a dynamic system, growing with each edition. It has been prompt in accommodating new topics. The advantages of updating existing headings, however, must be balanced against implementation costs, which are substantial. Still, a steady effort has been made to render the system responsive to societal changes and evolving language usage. A measure toward this end is that since the mid-1980s, in order to ensure the usefulness of LCSH to the library community at large, the Library of Congress has invited outside libraries to contribute headings to the system; more than 75 libraries worldwide now do this through SACO, the Subject Authority Cooperative Program.
Although it is generally acknowledged by information professionals that LCSH is far from an ideal system, its growth is a mark of success. In spite of its internal inconsistency and certain characteristics that still cater more to manual than to online systems, LCSH, which continues to evolve, has clearly demonstrated its versatility over a wide range of conditions and is not only holding its own but growing in popularity. Over the course of this century, LCSH has pushed forward steadily, offering subject access to a wide range of audiences in a wide range of environments, from the print environment to the electronic and online environment, from libraries to other venues of information providers. Its sphere of influence has expanded from the Library itself to the entire nation and to many parts of the world.
LCSH was born as the Library prepared to meet the challenges of the approaching 20th century. Its history supports the prediction that as another new century approaches, LCSH will continue -- with vigilance, flexibility and adaptability -- to evolve as needed to accommodate changing information resources and changing demands on and for information. Only this time, not as a newborn but as a mature system that has stood the test of many changing environments.
J.C.M. Hanson. 1909. The Subject Catalogs of the Library of Congress. Bulletin of the American Library Association 3:385-97.
Ms. Chan is a professor at the University of Kentucky and author of the standard textbook on the LCSH.