The Library of Congress Classification (LCC) is a system of library classification developed by the Library of Congress. It is used by most research and university libraries in the U.S. (and several other countries), although most public libraries continue to use the Dewey Decimal Classification (DDC).

The classification was originally developed by Herbert Putnam with the advice of Charles Ammi Cutter in 1897 before he assumed the librarianship of Congress. It was influenced by Cutter Expansive Classification and DDC, designed for the use by the Library of Congress. The new system replaced a fixed location system developed by Thomas Jefferson. By the time of Putnam's departure from his post in 1939 all the classes except K (Law) and parts of B (Philosophy and Religion) were well developed. It has been criticized as lacking a sound theoretical basis; many of the classification decisions were driven by the particular practical needs of that library, rather than considerations of rationality. In particular, the classification often shows bias towards the United States and towards Christianity.

Although it divides subjects into broad categories, it is essentially enumerative in nature.

The National Library of Medicine uses unused letters W and late Qs. Some libraries use NLM in conjuction with LCC, not using LCC's R (Medicine).

Wikipedia organized by the Library of Congress Classification

AGENERAL WORKS
BPHILOSOPHY. PSYCHOLOGY. RELIGION
CAUXILIARY SCIENCES OF HISTORY
DHISTORY: GENERAL AND OLD WORLD
EHISTORY: AMERICA
  This class is not broken down into letter sub-classes.
11-143America
151-889United States
FHISTORY: AMERICA
  This class is not broken down into letter sub-classes.
1-975United States local history
1001-1145.2British America (including Canada)
Dutch America
1170French America
1201-3799Latin America, Spanish America and History of Brazil.
GGEOGRAPHY. ANTHROPOLOGY. RECREATION
HSOCIAL SCIENCES
JPOLITICAL SCIENCE
KLAW
LEDUCATION
MMUSIC AND BOOKS ON MUSIC
NFINE ARTS
PLANGUAGE AND LITERATURE
QSCIENCE
RMEDICINE
SAGRICULTURE
TTECHNOLOGY
UMILITARY SCIENCE
VNAVAL SCIENCE
ZBIBLIOGRAPHY. LIBRARY SCIENCE. INFORMATION RESOURCES (GENERAL)

Letter classes I, O, W, X and Y are not standardly used.

See also: Wikipedia organised according to Roget's Thesaurus outline

External links