The Library of Congress Call Number System

Books and other materials in the ORU library are primarily organized using Library of Congress (LC) call numbers, a classification system according to subject. The LC classification system "was first developed in the late nineteenth and early twentieth centuries to organize and arrange the book collections of the Library of Congress." opens new windowLC Website

Books about similar subjects will have a similar call number, so once you locate a book on the shelf, look at the books to the right and left.

There are 21 major subject categories, or divisions, in the LC call number system, represented by English letters. The first and second letters of a call number represent just the first line on the call number label. Additional numbers and letters that further define a book are usually included in the call number.

The first letter of the call number represents a major category or subject. For example, a call number that begins with "B" represents the subjects of "Philosophy, Psychology, Religion, and Theology."

The second letter of a call number represents the specific sub-section within the general subject area. As shown in the shortened outline to the right, materials with call numbers beginning with "BR" are on the subject of "Church History," a subdivision under "B--Philosophy, Psychology, Religion."

Library of Congress Classification Outline

Go to the complete opens new windowLibrary of Congress Classification Outline and drill down through the subjects to identify call numbers sections in your area of interest.

Library of Congress Label Visualization

opens new windowLibrary of Congress Names
- View alternative, broader, and narrower terms. Key in a term, select a heading, then click Search. Choose a "Label" then click the "Visualization" tab.
- For subject headings, key in your search term, select LC Subject Headings, and then click .

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