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
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 .
Did you know?
The Library of Congress has archived Twitter tweets.
- opens new window"Library of Congress Plans to Archive all Twitter Posts" (USA Today, April 15, 2010)
- opens new windowTwitter Donates the Entire Tweet Archive to the Library of Congress (LC website, April 15, 2010)
- opens new windowThe Library and Twitter: An FAQ (Library of Congress Blog, April 28, 2010)
- opens new window"Library of Congress to Archive Twitter" (American Libraries, June/July 2010)
- opens new window"LOC Twitter Archive Grows to 170 Billion" (Library Journal, Feb. 1, 2013)
- opens new window"Library of Congress will no longer archive every tweet" (U.S.News online, Dec. 27, 2017)