Using reference books such as encyclopedias and historical dictionaries is an excellent way to begin your research. Encyclopedia and historical dictionary articles provide broad overviews of topics, critical questions and issues about topics, and bibliographies.
Search the USD Library Catalog for reference works. For example, enter United States History Encyclopedias as a subject search and browse the results.
Also, see the various e-reference works history databases in the Research Gateway.
Use WorldCat to find books in other libraries through the world. Click on the "Request Item" button in the record of any book you wish to order.
Use ILLiad to request books that you find in the WorldCat catalog. If you don't have an ILLiad account, sign up now.
Library of Congress Classifications (call numbers) can help you locate books and browse through possible topic areas. After searching the catalog use these call numbers to browse other books that might be of interest.
Theses and dissertations can be searched online through Proquest.