The classification was invented by Herbert Putnam in 1897, just before he assumed the librarianship of Congress. With advice from Charles Ammi Cutter, it was influenced by his Cutter Expansive Classification, the Dewey Decimal System, and the Putnam Classification System (developed while Putnam was head librarian at the Minneapolis Public Library).^[2][3] It was designed specifically for the purposes and collection of the Library of Congress to replace the fixed location system developed by Thomas Jefferson. By the time Putnam departed from his post in 1939, all the classes except K (Law) and parts of B (Philosophy and Religion) were well developed.

LCC has been criticized for lacking a sound theoretical basis; many of the classification decisions were driven by the practical needs of that library rather than epistemological considerations.^[4] Although it divides subjects into broad categories, it is essentially enumerative in nature. That is, it provides a guide to the books actually in one library's collections, not a classification of the world.

In 2007 The Wall Street Journal reported that in the countries it surveyed most public libraries and small academic libraries used the older Dewey Decimal Classification system.^[1]

The National Library of Medicine classification system (NLM) uses the initial letters W and QS–QZ, which are not used by LCC. Some libraries use NLM in conjunction with LCC, eschewing LCC's R for Medicine. Others use LCC's QP–QR schedules and include Medicine R.{{clarify|date=May 2012}}^[5][6]

Classification

Class A – General Works

• Subclass AC – Collections. Series. Collected works
• Subclass AE – Encyclopedias
• Subclass AG – Dictionaries and other general reference works
• Subclass AI – Indexes
• Subclass AM – Museums. Collectors and collecting
• Subclass AN – Newspapers
• Subclass AP – Periodicals
• Subclass AS – Academies and learned societies
• Subclass AY – Yearbooks. Almanacs. Directories
• Subclass AZ – History of scholarship and learning. The humanities

Class B – Philosophy. Psychology. Religion

• Subclass B – Philosophy (General)
• Subclass BC – Logic
• Subclass BD – Speculative philosophy
• Subclass BF – Psychology
• Subclass BH – Aesthetics
• Subclass BJ – Ethics
• Subclass BL – Religions. Mythology. Rationalism
• Subclass BM – Judaism
• Subclass BP – Islam. Bahaism. Theosophy, etc.
• Subclass BQ – Buddhism
• Subclass BR – Christianity
• Subclass BS – The Bible
• Subclass BT – Doctrinal theology
• Subclass BV – Practical Theology
• Subclass BX – Christian Denominations

Class C – Auxiliary Sciences of History

• Subclass C – Auxiliary Sciences of History
• Subclass CB – History of Civilization
• Subclass CC – Archaeology
• Subclass CD – Diplomatics. Archives. Seals
• Subclass CE – Technical Chronology. Calendar
• Subclass CJ – Numismatics
• Subclass CN – Inscriptions. Epigraphy
• Subclass CR – Heraldry
• Subclass CS – Genealogy
• Subclass CT – Biography

Class D – World History and History of Europe, Asia, Africa, Australia, New Zealand, etc.

• Subclass D – History (General)
• Subclass DA – Great Britain
• Subclass DAW – Central Europe
• Subclass DB – Austria – Liechtenstein – Hungary – Czechoslovakia
• Subclass DC – France – Andorra – Monaco
• Subclass DD – Germany
• Subclass DE – Greco-Roman World
• Subclass DF – Greece
• Subclass DG – Italy – Malta
• Subclass DH – Low Countries – Benelux Countries
• Subclass DJ – Netherlands (Holland)
• Subclass DJK – Eastern Europe (General)
• Subclass DK – Russia. Soviet Union. Former Soviet Republics – Poland
• Subclass DL – Northern Europe. Scandinavia
• Subclass DP – Spain – Portugal
• Subclass DQ – Switzerland
• Subclass DR – Balkan Peninsula
• Subclass DS – Asia
• Subclass DT – Africa
• Subclass DU – Oceania (South Seas)
• Subclass DX – Romanies

Class E – History of the Americas

• Class E does not have any subclasses.

Class F – Local History of the Americas

• Class F does not have any subclasses, however Canadian Universities and the Canadian National Library use FC for Canadian History, a subclass that the LC has not officially adopted, but which it has agreed not to use for anything else^[7][8]

Class G – Geography, Anthropology, Recreation

• Subclass G – Geography (General). Atlases. Maps
• Subclass GA – Mathematical geography. Cartography
• Subclass GB – Physical geography
• Subclass GC – Oceanography
• Subclass GE – Environmental Sciences
• Subclass GF – Human ecology. Anthropogeography
• Subclass GN – Anthropology
• Subclass GR – Folklore
• Subclass GT – Manners and customs (General)
• Subclass GV – Recreation. Leisure

Class H – Social Sciences

• Subclass H – Social sciences (General)
• Subclass HA – Statistics
• Subclass HB – Economic theory. Demography
• Subclass HC – Economic history and conditions
• Subclass HD – Industries. Land use. Labor
• Subclass HE – Transportation and communications
• Subclass HF – Commerce
• Subclass HG – Finance
• Subclass HJ – Public finance
• Subclass HM – Sociology (General)
• Subclass HN – Social history and conditions. Social problems. Social reform
• Subclass HQ – The family. Marriage, Women and Sexuality
• Subclass HS – Societies: secret, benevolent, etc.
• Subclass HT – Communities. Classes. Races
• Subclass HV – Social pathology. Social and public welfare. Criminology
• Subclass HX – Socialism. Communism. Anarchism

Class J – Political Science

• Subclass J – General legislative and executive papers
• Subclass JA – Political science (General)
• Subclass JC – Political theory
• Subclass JF – Political institutions and public administration
• Subclass JJ – Political institutions and public administration (North America)
• Subclass JK – Political institutions and public administration (United States)
• Subclass JL – Political institutions and public administration (Canada, Latin America, etc.)
• Subclass JN – Political institutions and public administration (Europe)
• Subclass JQ – Political institutions and public administration (Asia, Africa, Australia, Pacific Area, etc.)
• Subclass JS – Local government. Municipal government
• Subclass JV – Colonies and colonization. Emigration and immigration. International migration
• Subclass JX – International law, see JZ and KZ (obsolete)
• Subclass JZ – International relations

Class K – Law

• Subclass K – Law in general. Comparative and uniform law. Jurisprudence
• Subclass KB – Religious law in general. Comparative religious law. Jurisprudence
• Subclass KBM – Jewish law
• Subclass KBP – Islamic law
• Subclass KBR – History of canon law
• Subclass KBS – Canon law of Eastern churches
• Subclass KBT – Canon law of Eastern Rite Churches in Communion with the Holy See of Rome
• Subclass KBU – Law of the Roman Catholic Church. The Holy See
• Subclasses – KD/KDK - United Kingdom and Ireland
• Subclass KDZ – America. North America
• Subclass KE – Canada
• Subclass KF – United States
• Subclass KG – Latin America – Mexico and Central America – West Indies. Caribbean area
• Subclass KH – South America
• Subclasses KJ-KKZ – Europe
• Subclasses KL-KWX – Asia and Eurasia, Africa, Pacific Area, and Antarctica
• Subclass KU/KUQ – Law of Australia and New Zealand
• Subclass KZ – Law of nations

Class L – Education

• Subclass L – Education (General)
• Subclass LA – History of education
• Subclass LB – Theory and practice of education
• Subclass LC – Special aspects of education
• Subclass LD – Individual institutions – United States
• Subclass LE – Individual institutions – America (except United States)
• Subclass LF – Individual institutions – Europe
• Subclass LG – Individual institutions – Asia, Africa, Indian Ocean islands, Australia, New Zealand, Pacific islands
• Subclass LH – College and school magazines and papers
• Subclass LJ – Student fraternities and societies, United States
• Subclass LT – Textbooks

Class M – Music

• Subclass M – Music
• Subclass ML – Literature on music
• Subclass MT – Instruction and study

Class N – Fine Arts

• Subclass N – Visual arts
• Subclass NA – Architecture
• Subclass NB – Sculpture
• Subclass NC – Drawing. Design. Illustration
• Subclass ND – Painting
• Subclass NE – Print media
• Subclass NK – Decorative arts
• Subclass NX – Arts in general

Class P – Language and Literature

• Subclass P – Philology. Linguistics
• Subclass PA – Greek language and literature. Latin language and literature
• Subclass PB – Modern languages. Celtic languages and literature
• Subclass PC – Romanic languages
• Subclass PD – Germanic languages. Scandinavian languages
• Subclass PE – English language
• Subclass PF – West Germanic languages
• Subclass PG – Slavic languages and literatures. Baltic languages. Albanian language
• Subclass PH – Uralic languages. Basque language
• Subclass PJ – Oriental languages and literatures
• Subclass PK – Indo-Iranian languages and literatures
• Subclass PL – Languages and literatures of Eastern Asia, Africa, Oceania
• Subclass PM – Hyperborean, Native American, and artificial languages
• Subclass PN – Literature (General)
• Subclass PQ – French literature – Italian literature – Spanish literature – Portuguese literature
• Subclass PR – English literature
• Subclass PS – American literature
• Subclass PT – German literature – Dutch literature – Flemish literature since 1830 – Afrikaans literature -Scandinavian literature – Old Norse literature: Old Icelandic and Old Norwegian – Modern Icelandic literature – Faroese literature – Danish literature – Norwegian literature – Swedish literature
• Subclass PZ – Fiction and juvenile belles lettres

Class Q – Science

• Subclass Q – Science (General)
• Subclass QA – Mathematics
• Subclass QB – Astronomy
• Subclass QC – Physics
• Subclass QD – Chemistry
• Subclass QE – Geology
• Subclass QH – Natural history – Biology
• Subclass QK – Botany
• Subclass QL – Zoology
• Subclass QM – Human anatomy
• Subclass QP – Physiology
• Subclass QR – Microbiology

Class R – Medicine

• Subclass R – Medicine (General)
• Subclass RA – Public aspects of medicine
• Subclass RB – Pathology
• Subclass RC – Internal medicine
• Subclass RD – Surgery
• Subclass RE – Ophthalmology
• Subclass RF – Otorhinolaryngology
• Subclass RG – Gynecology and Obstetrics
• Subclass RJ – Pediatrics
• Subclass RK – Dentistry
• Subclass RL – Dermatology
• Subclass RM – Therapeutics. Pharmacology
• Subclass RS – Pharmacy and materia medica
• Subclass RT – Nursing
• Subclass RV – Botanic, Thomsonian, and Eclectic medicine
• Subclass RX – Homeopathy
• Subclass RZ – Other systems of medicine

Class S – Agriculture

• Subclass S – Agriculture (General)
• Subclass SB – Horticulture. Plant propagation. Plant breeding
• Subclass SD – Forestry. Arboriculture. Silviculture
• Subclass SF – Animal husbandry. Animal science
• Subclass SH – Aquaculture. Fisheries. Angling
• Subclass SK – Hunting

Class T – Technology

• Subclass T – Technology (General)
• Subclass TA – Engineering Civil engineering (General).
• Subclass TC – Hydraulic engineering. Ocean engineering
• Subclass TD – Environmental technology. Sanitary engineering
• Subclass TE – Highway engineering. Roads and pavements
• Subclass TF – Railroad engineering and operation
• Subclass TG – Bridges
• Subclass TH – Building construction
• Subclass TJ – Mechanical engineering and machinery
• Subclass TK – Electrical engineering. Electronics. Nuclear engineering
• Subclass TL – Motor vehicles. Aeronautics. Astronautics
• Subclass TN – Mining engineering. Metallurgy
• Subclass TP – Chemical technology
• Subclass TR – Photography
• Subclass TS – Manufacturing engineering. Mass production
• Subclass TT – Handicrafts. Arts and crafts
• Subclass TX – Home economics

Class U – Military Science

• Subclass U – Military science (General)
• Subclass UA – Armies: Organization, distribution, military situation
• Subclass UB – Military administration
• Subclass UC – Military maintenance and transportation
• Subclass UD – Infantry
• Subclass UE – Cavalry. Armor
• Subclass UF – Artillery
• Subclass UG – Military engineering. Air forces
• Subclass UH – Other military services

Class V – Naval Science

• Subclass V – Naval science (General)
• Subclass VA – Navies: Organization, distribution, naval situation
• Subclass VB – Naval administration
• Subclass VC – Naval maintenance
• Subclass VD – Naval seamen
• Subclass VE – Marines
• Subclass VF – Naval ordnance
• Subclass VG – Minor services of navies
• Subclass VK – Navigation. Merchant marine
• Subclass VM – Naval architecture. Shipbuilding. Marine engineering

Class Z – Bibliography, Library Science

• Subclass Z – Books (General). Writing. Paleography. Book industries and trade. Libraries. Bibliography
• Subclass ZA – Information resources/materials

See also

• ACM Computing Classification System
• Brinkler classification
• Chinese Library Classification
• Comparison of Dewey and Library of Congress subject classification
• Harvard–Yenching Classification
• ISBN
• Minnie Earl Sears, formulated Sears Subject Headings, simplified for use by small libraries
• Database of Recorded American Music
• Books in the United States

Notes

References

External links

• [https://www.loc.gov/catdir/cpso/lcco/ Library of Congress classification outline], loc.gov
• [https://www.loc.gov/aba/cataloging/classification/ Library of Congress – classification], loc.gov
• [https://www.loc.gov/cds/ Cataloging Distribution Services] – source of Library of Congress Classification schedules. loc.gov
• [https://www.loc.gov/catdir/cpso/lcco/lcco.html Classification outline], loc.gov
• [https://web.archive.org/web/20140412225645/http://geography.about.com/library/congress/blhowto.htm How to read LCC call numbers], geography.about.com (via The Wayback Machine)
• How to use LCC to organize a home library, zackgrossbart.com