So now we know that LC Classification is based on the subject matter of a book. We know that it's easier to find things this way, and we've also looked at some examples in the online catalog. This brings us to another important part of how to find a book: the classification table.

Books and other library materials are arranged according to their subject matter to make it easier for you to find things based on their topic. The Library of Congress system was based on a collection of over one million books and incorporated the best parts of all the classification systems in use at the time.

Library of Congress numbers always start with letters of the alphabet, which represent the subject of the work. Books, videos, etc., are organized according to 21 branches of knowledge, using the letters A-Z, except I, O, W, X, and Y. The subjects can be further divided using one or two more letters and a set of numbers.

Knowing the letters for your subject area gives you a place to start browsing the shelves. Which letters represent your subject? Let's look at how these subjects can be sub-divided in the Library of Congress Classification Table.