Older newspaper articles can be more difficult to find than current ones. Some options include:
New York Times Archive: You can search this site to locate articles on a topic and view a short summary. Once you have the citation information, you can request a specific article through the library’s Document Delivery Service (DDS) to get an electronic copy. (For help with DDS, consult Requesting an item that NAU doesn't have.)
Chronicling America: A Library of Congress site that enables you to search and access digitized US newspapers from 1836-1922.
Historical Arizona Newspapers: Provides access to some digitized Arizona newspapers.