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How to Find Books Using the Library of Congress Classification System: Home

What is the Library of Congress Classification System

The Library of Congress Classification system (LCC) is the system librarians use to create call numbers, the string of numbers and letters that tell you where the book is located in the library. The LCC system assigns subjects into 21 classes which are each represented by a letter. This means that items that share the same subject will be placed near each other. For example, the call number for books about music will start with M and will be located in the same place in the library. 

Most subjects are further broken down into subclasses which represent more specific subjects. For example agriculture is broken into six subclasses: Agriculture (General): S; Plant culture: SB; Forestry: SD; Animal culture: SF; Aquaculture, Fisheries and Angling: SH; and Hunting Sports: SK. A call number will generally begin with the letters representing the subclass. For example, the book Planting for the Future: Forestry for Human Needs by Erik Eckholm has the call number SD381 .E33. The letters "SD" indicate that this book is about forestry. The subclasses narrow down where a book will be located in the library. 

The majority of books are located on the 1st floor of the library (1 floor below the library entrance and service desks). Some items such as DVDs, new books, graphic novels, juvenile fiction, YA literature, and reference books are located on the 2nd floor. Fun fact: Most popular fiction call numbers start with "P".

Library of Congress Classification Key

A = General Works

B = Philosophy, Psychology, Religion

C = Auxiliary Sciences of History

D = History: Europe, Asia, Africa

E-F = History: America

G = Geography, Anthropology, Recreation

H = Social Sciences

J = Political Science

K = Law

L = Education

M = Music

N = Fine Arts

P = Languages and Literature

Q = Science

R = Medicine

S = Agriculture

T = Technology

U = Military Science

V= Naval Science

Z= Bibliography, Library Science, Information Resources

Browsing in the Library Tutorial

1. Start by looking up what letter represents the subject you are looking for. You can find the classification key on this page or on "Find It" posters and bookmarks in the library. For example, if you are looking for a book about psychology and creativity, you want to look for call numbers that start with the letter B because B represents the subjects philosophy, psychology and religion.

2. Next, look for the subclass that best matches your subject. You can find this information on the "Find It" posters at the ends of some shelves in the library. The subclass for psychology is BF. 

Poster showing list of Library of Congress headings and subject headings with "Find It" written on the side

3. Look for that subclass on the signs at the ends of the bookshelves in the library. The signs indicate what range of call numbers are represented on that shelf. One side of this shelf has books from BF 692.2 M to BJ 1012 L. The other side of the shelf has books with call numbers from BF 311 G to BF 692.2 L. Since we are looking for books on psychology which uses call numbers starting with "BF" books about psychology and creativity could be on either side of the shelf. 

Bookshelf which has label that says "Circulating Books" at the top and two labels on the sides indicating what call numbers are represented on the bookshelf

4. Browse the shelves for titles that match your subject of interest. Here is a selection of books about the topic psychology and creativity which are all located on the same shelf. 

A selection of books on the psychology of creativity, all with call numbers that begin with "BF"

5. Once you have found books that match your subject of interest you can evaluate the physical books to determine which books will be most applicable to your research question or topic of interest. Look at the title, author's credentials, table of contents and bibliographies to determine which books best match your research needs. 

6. If you don't see a book that you are interested in, always feel free to ask a librarian for help. 

How to Find Specific Books in the Library

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