The Mark O. Hatfield Library uses the Library of Congress classification system to group items with similar topics together. Each item is assigned a unique call number, which helps people to locate material on the shelf. The Library of Congress uses a combination of letters and numbers, and each call number begins with a letter.
To the right are the general call numbers and the main topics within the Library of Congress system. Click on any class to view an outline of its subclasses in an interactive PDF document.
This list is based off of the Library of Congress Classification Outline.
Below are key reference books that provide a general overview of a topic or help identify synonyms, related terms, or basic data. These sources often include references and lists of further readings.