Library of Congress Classification

System of library organization developed during the reorganization of the U.S. Library of Congress. It consists of separate, mutually exclusive, special classifications, often having no connection save the accidental one of alphabetical notation.

The arrangement roughly follows groupings of social sciences, humanities, and natural and physical sciences. It divides the field of knowledge into 20 large classes and an additional class for general works. Each main class has a synopsis that also serves as a guide. The resulting order is from the general to the specific and from the theoretical to the practical. The LC Classification has largely replaced the Dewey Decimal Classification in university, special, and government libraries.