Some call numbers start with letters while others start with numbers. Why? How do I find these books?
Library of Congress Call Numbers
Books on the Main Level and the East, South, and West sides of the Intermediate Level stacks are classified in the Library of Congress call number system. This system was developed by the Library of Congress in Washington and is used by most academic and research libraries in the United States. It has been in continuous development since about 1900.
Books in the Library of Congress system are easy to identify because the call numbers begin with a letter or letters of the alphabet. Each letter represents a broad subject area. The letters or numbers which follow designate more specific subject areas. This means that books on the same or similar subjects will be shelved near each other.
Below is a brief overview of the Library of Congress Classification System. If you have any questions or problems finding a book, please ask for assistance at the Research Desk.
A | General Works |
B-BJ | Philosophy & Psychology |
BL-BX | Religion |
C | Auxilliary Sciences of History |
D | History: General and Old World (Eastern Hemisphere) |
E-F | History: America (Western Hemisphere) |
G | Geography. Maps. Anthropology. Recreation. |
H | Social Sciences. Economics. Business. Sociology. |
J | Political Science |
K | Law |
L | Education |
M | Music |
N | Fine Arts |
P-PA | General Philology and Linguistics. Classical Languages and Literatures. |
PB-PH | Modern European Languages |
PJ-PM | Languages and Literature of Asia, Africa, Oceania. Native American languages. Artificial languages. |
PN | Literature (General) |
PQ | French, Italian, Spanish and Portuguese Literatures |
PR-PS | English and American Literatures |
PT | German, Dutch, and Scandinavian Literatures |
Q | Science |
QA-QB | Mathematics. Computer Science. Astronomy. |
QC-QD | Physics. Chemistry. |
QE | Geology |
QH-QL | Biology. Botany. Zoology. |
QM-QR | Human Anatomy. Physiology. Microbiology. |
R | Medicine |
S | Agriculture |
T | Technology. Engineering. Aeronautics. |
U | Military Science. |
V | Naval Science |
Z |
Bibliography. Library Science. |
Dewey Decimal Call Numbers
Melvil Dewey (1851 - 1931) developed this system while working at the Amherst College Library. It is used mostly by public and school libraries in the United States. It first appeared in 1876.
Books in the Dewey Decimal system are easy to identify because the call numbers begin with numbers.
Note: In McFarlin Library, the Dewey collection contains older books, added to the library's collection before 1984. Books added since 1984 are found in the Library of Congress stacks. The majority of the library's Dewey books have now been reclassified into the Library of Congress system.
If you have any questions or problems finding a Dewey book, please ask for assistance at the Research Desk.
Superintendent of Documents (SuDoc) numbers
In addition to the Library of Congress and Dewey books, the Library has a third call number system in use with the Government Documents. Items in Government Documents are shelved according to their Superintendent of Documents (or SuDoc) number. This is a unique number assigned by the federal government to every item it publishes. The number is based on the issuing agency. Below is a brief overview of the SuDoc numbering system. If you have any questions or problems finding a document, please ask for assistance.
A | Agriculture Department |
C3 | Census Bureau |
D | Defense Department |
E | Energy Department |
E | Education Department |
GA | General Accounting Office |
GS | General Services Administration |
HE | Health and Human Services |
I | Interior Department |
I19 | U.S. Geological Survey |
J | Justice Department |
Ju | Judiciary |
L | Labor Department |
LC | Library of Congress |
NAS | National Aeronautics and Space Administration |
S | State Department |
SI | Smithsonian Institution |
T22 | Internal Revenue Service |
X,Y | Congress |
Y4 | Congressional Committees |
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