Library of Congress Control Number
November 28, 2021
The Library of Congress Control Number or LCCN (or also LC) is a serial card numbering system in the United States Library of Congress catalog. It has nothing to do with the content of the books, and is not to be confused with the Library of Congress Classification.
The LCCN numbering system has been in use since 1898, when the acronym LCCN originally stood for Library of Congress Card Number. It was also called the Library of Congress Catalog Card Number. The Library of Congress prepared bibliographic information cards for its library catalog with the intention also of selling duplicates of the same cards to other libraries for use in their catalogs. This is known as centralized cataloging. Each card was given a serial number to help identify it.
Although most bibliographic information is now created electronically, stored and shared with other libraries, there is still a need to identify each individual record, and the LCCN continues to perform this function.
Librarians around the world use this unique identification system in the cataloging process of most books that have been published in the United States. This helps them obtain the correct cataloging data (known as cataloging records), which the Library of Congress and other sources make available on the Web and through their media.
In February 2008, the Library of Congress created the LCCN Permalink service, providing a fixed URL for all Library of Congress Control Numbers.
In its most basic form the number includes a year and a serial number. The year has two digits from 1898 to 2000, and four digits starting 2001. The ambiguous three years are differentiated by the length of the serial number. There are also some quirks in numbers starting with "7" due to a failed experiment used between 1969 and 1972.
Serial numbers consist of six digits and should include leading zeros. The hyphen, which is often seen to separate the year from the serial number, is optional. More recently, the Library of Congress begged publishers not to include a hyphen.
Gemeinsame Normdatei (GND)
International Standard Book Number (ISBN)
Structure of the LC Control Number, on loc.gov.
LCCN Permalink FAQ, at lccn.loc.gov.
Search the catalog to search for an LCCN