This research guide:
Historical newspapers:
If you have additional questions about using these online resources, please contact a librarian for assistance.
Chronicling America (national level)
Chronicling America is a collection of over 600 newspapers from 30 states published between the 1830s and 1922, and it continues to grow rapidly. Backed by the Library of Congress and the National Endowment for the Humanities, these newspapers are all freely available. Although each state on the Historical Newspapers by State page indicates if Chronicling America includes newspapers from it, this site also allows you to search all Chronicling America newspapers simultaneously.
Google Newspapers (national level)
Google once indicated an interest in digitizing all the world's written information. Having digitized a significant number of newspapers, Google gave up. The old historical newspaper archive search interface is defunct and was replaced by this one. An alphabetical listing of the historical newspapers in Google Archives is available here.
NewspaperCat (U.S. and Caribbean)
A University of Florida project called NewspaperCat seems to have ingested all the U.S. and Caribbean newspapers and made them searchable by title, language and place of publication.