The Library of Congress has updated the Chronicling America: Historic American Newspapers site, adding an additional 178,000 pages (including 25 new newspapers). A preview of upcoming changes to the Web site itself, including a new overall look, a "100 Years Ago Today" daily slide show, new search features, and improved results navigation, is also being added. The beta version is available here.
I posted an overview of the Chronicling America: Historic American Newspapers here last summer, which you can read here.
Chronicling America is produced by the National Digital Newspaper Program (NDNP), a partnership between the National Endowment for the Humanities and the Library of Congress.
A great site – if you haven't been lately, you might want to revisit.