Library of Congress Classification (LCC)
The Library of Congress Classification (LCC) is a systematic approach to organizing library materials, developed by the United States Library of Congress in the late 19th century. Originally initiated by Herbert Putnam and Charles Martel, the LCC was created to catalog the extensive collection of the Library of Congress, which is the largest library globally, housing over one hundred million items. Launched in 1914, the LCC divides materials into twenty-one main categories, each represented by a unique letter corresponding to different academic disciplines such as history, social science, and law. Within these categories, further subdivisions allow for more specific organization, using combinations of letters and numbers to detail various topics and genres.
The LCC is not a mandatory national system but has been widely adopted by many academic and large public libraries, while smaller libraries often stick with the Dewey Decimal Classification (DDC). Unlike the DDC, which organizes knowledge into a rigid numeric system, the LCC employs a flexible alphanumeric structure that reflects the diverse and evolving nature of its catalog. This adaptability has allowed the LCC to incorporate new subjects, such as technology, into its framework over time. With regular updates issued by the LOC, the LCC aims to provide a comprehensive and accessible method for organizing library collections, catering to a variety of research and information needs.
Library of Congress Classification (LCC)
The Library of Congress Classification (LCC) is a system of organizing books and other materials that was developed by the United States Library of Congress (LOC). The LCC system was initially developed by Herbert Putnam, the librarian of Congress, and Charles Martel, the chief classifier in the LOC's Catalogue Division, to specifically organize the holdings at the LOC.
The development of the LCC system began in 1898 and was first offered as a published system of book categorization in 1914. It is regarded by the LOC as a subject authority list for use within its own holdings and not as a requisite national system of book organization. It has been adopted for broader use in the United States by academic institutions, specialized libraries, and large public libraries. It is also used by many international institutions. Many small public libraries still rely on the Dewey Decimal Classification (DDC) system.
History
The Library of Congress was founded in 1800 to serve as the official national library of the United States. It is the largest library in the world, with more than one hundred million distinct items in both digital and physical formats. In 1897, as the contents of the LOC were moved to the Thomas Jefferson Building (one of three current LOC buildings), the then librarian of Congress, John Russell Young, recognized the poor organization of the LOC and established protocols to create an organizational structure that would ease the public's access to its materials. After two years, he was succeeded by Herbert Putnam, who instituted a system of using three-by-five-inch library cards to catalogue each book at the LOC. He then sold annual editions of the accumulated card catalogues at cost to library branches across the country. As a result, American libraries began to use the same cataloguing numbers, with the LOC viewed as the national authority on such issues.
Under Putnam and Martel's direct oversight, the LOC created a revised system that relied upon researchers, the LOC's cataloguers, editors, policy specialists, and other authorities to organize books in its collection. The system was known as the Library of Congress Classification (LCC).
Organization
The LCC divides all materials first by category and then by subclass. There are twenty-one basic categories, each of which corresponds to a major discipline or area of academic interest, such as world history, social science, political science, law, education, and general reference. These classes are each assigned a unique letter of the alphabet. For instance, "General Works," which includes reference books, newspapers, and journals are coded under the letter "A," while the related fields of philosophy, psychology, and religion are all categorized under the letter "B."
These categories are then subdivided into a series of corresponding specialties, such as topic, form, place, or time period. Each of these specialties follows its own internal logic, so that the organization of books under the letter "A" does not follow the same pattern as those categorized under "B." This lack of corresponding organization between the various specialties was not a conscious decision, but rather the result of a lengthy, continually evolving process that independently considered the input of specialists in each category.
Books placed under each subdivision are given matching two- or three-letter codes that come after the initial letter. For instance, in the "B" category of philosophy, psychology, and religion materials, all philosophy books are separated into a grouping of one category and two disciplines: "B" (General), "BC" (Logic), or "BD" (Speculative Philosophy). Religion, on the other hand, which stretches from "BL" to "BX," is more focused upon specialized categories, such as the various religious traditions, the Bible, doctrinal theology, and practical theology. For example, each major religion is given its own two-letter set of call letters, such as "BM" for Judaism, "BP" for Islam, "BQ" for Buddhism, and "BR" for Christianity.
Each of these subdivisions is then further split into more specific topics. In the case of Judaism, BM1 through BM449 are categorized as "General Studies" of Judaism. More explicitly, BM1 through BM69 are studies of Judaism as a whole, while the following numbers focus on more refined topics such as the study and teaching of Judaism (BM70 to BM135) and the history of Judaism (BM150 to BM449).
Like the Dewey Decimal system, the LCC uses a decimal point, and the numbers and letters after the decimal point use a combination of the author's name, the year the book was published, the edition, and other factors that determine a book's final LCC code.
The LCC has remained flexible so that it can incorporate more subjects as time passes, a system that has enabled it to include books focused upon computers and other technological advances within its framework. To account for these changes, the LOC produces a quarterly publication detailing all changes and additions to the LCC outline. The LCC schedule is available for free online on the Library of Congress's website.
Differences between the LCC and the DDC
The Dewey Decimal system was designed by American librarian Melvil Dewey in 1876. Beyond the fact that the DDC primarily uses numeric notations to categorize books—as opposed to the alphanumeric system of the LCC—the primary difference between the two systems lies in their origins. The DDC was designed to organize knowledge; the LCC was developed to catalogue a single, specific library.
The DDC is divided into ten classes of disciplines or fields of study. These ten classes are then separated into ten divisions, with these ten divisions split into ten sections. The DDC uses the same logic system to categorize all books within its various subdivisions. Reference books about any of the ten broadest categories, for example, will be found in roughly the same place within each class.
Bibliography
Chan, Lois Mai. Cataloging and Classification: An Introduction. 3rd ed. Lanham: Scarecrow, 2007. 213–56; 375–409. Print.
"Dewey Decimal System vs. Library of Congress: What's the Difference?" Study.com, 9 Dec. 2010, study.com/articles/Dewey‗Decimal‗System‗vs‗Library‗of‗Congress‗Whats‗the‗Difference.html. Accessed 7 Feb. 2025.
"Frequently Asked Questions: The Dewey Program at the Library of Congress." Library of Congress, www.loc.gov/aba/dewey/faq.html. Accessed 7 Feb. 2025.
"Historical Note on the Library of Congress Classification." Cataloger's Reference Shelf, www.itsmarc.com/crs/mergedprojects/scmclass/scmclass/historical‗note‗on‗the‗library‗of‗congress‗classification‗scm.htm. Accessed 7 Feb. 2025.
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