Dewey Decimal System

The Dewey Decimal system is a number-based system that we use for organizing books into categories. Dewey is broken down into ten mail categories, and each of those is broken into ten, and so on. The chart below will give you an overview of what's in each category.

The more specific your number gets (say, 973.775 instead of 900), the more specific your topic is:

900 is History & Geography

970 is History of North America

973 is the United States

973.7 is the American Civil War

973.77 is Civil War Hospitals, Charities, and Prisons

973.775 is the book Women doctors and nurses of the Civil War.

For a complete list (to the ones place) of Dewey categories, visit OCLC's Dewey Summaries page.