Most items in the Library are given a collection location and a call number according to an established classification system. Since 1971, Andover-Harvard has been using the Library of Congress classification system. Before 1971 we used our own classification system (which we now call OLD DIV).
All LC call numbers begin with one to three letters (usually two) followed by numbers (on the book labels these numbers appear on the second line). This part of the call number, called the "class mark," locates the item on the shelves within its assigned subject.
The second part of the call number usually designates the author. It is the first letter of the author's last name followed by numbers assigned by the catalogers to keep works within a subject area in alphabetical order by author. Sometimes the second part of the call number is a further subject designation. These combinations of letters with numbers are called "Cutter numbers" after Charles Ammi Cutter. Often the call numbers include dates that help to distinguish various editions and printings. Volume and copy numbers may also be found in the call number and/or as part of the designations on the label that locate the item on the shelves.
The Library of Congress Classification scheme was developed by James C.M. Hanson and implemented by Charles Martel for the Library of Congress around the turn of the 20th century. It was based on and influenced by the classification scheme devised by Charles Ammi Cutter. Hanson and Martel did not see the system as a "scientific order of subjects" but rather a "convenient sequence of the various groups ... of books" (Report of the Librarian of Congress for the Fiscal Year Ending June 30, 1901 , p. 234). It was originally devised as the classification only for the Library of Congress, but it has been adopted by many libraries, including most academic and research libraries in the United States. Andover-Harvard started using the LC classification system in 1971. Most printed items purchased, cataloged, or re-cataloged after 1970 are assigned LC call numbers. Many of these works were published prior to 1971. There are many items within the LC collection that were published prior to 1971.
We use the Library of Congress system because it is thorough and well-suited for an academic library such as ours. We also can take advantage of the fact that the Library of Congress and other academic libraries have already cataloged a portion of the books we receive. That means we do not have to come up with a new call number for every new book; for books not cataloged by the Library of Congress or by other libraries, catalogers in our library assign a call number after consulting the more than five feet of volumes that make up the classification system in printed form.
Contrary to popular belief, the Library of Congress does not have and catalog every book published in the world; many of the titles in Andover-Harvard are not held and, therefore, not cataloged by the Library of Congress.
Library of Congress Classification System
A1 General works, encyclopedias, indexes, almanacs
B Philosophy (General)
BD Speculative philosophy
BL General religion, mythology; Hinduism
BM Judaism (Dead Sea scrolls) (see also DS)
BP Islam (see also DS); Bahaism, Theosophy, etc.
BR General Christianity; Church history
BS Bible (BS700+ Hebrew Bible/Old Testament; BS1900+ New Testament)
BT Christian doctrinal theology (see also BR)
BV Christian practical theology (liturgy, missions, Christian education, preaching)
BX Orthodoxy, Roman Catholic Church, Protestantism
C-F General biography2, history, archaeology (DS Middle East)
G Geography, anthropology, folklore
H Social sciences (economics, sociology, etc.)
J-K Political science, law
P Languages (PA Greek & Latin; PJ Semitic languages)
U Military science
V Naval science
Z Books, manuscripts, libraries, bibliography 1, 2