Here at Concordia St. Paul we have access to the New York Times in digitized form from 1851 and up.* We also have full-text coverage from the 1980s and up to over 300 of the best-known U.S. newspapers through ProQuest Newsstand - albeit not in digitized form. Finally, Concordia's own student publications - going back to the 1920s - have been digitized (see here)
But what else it out there?
A few weeks ago, I heard the news that key historical newspapers from 1836-1922 had now been digitized by the Library of Congress and could be keyword searched from online. The project called Chronicling America: Historic Newspapers.
The Ohio Historical Society has done a series of helpful videos giving a tour of the database. The one called What is Chronicling America? is found below
For those newspapers that have already been digitized (a substantial amount) you can, for example, limit your search by state, ethnicity, and language. In addition to this, the Library of Congress also now has a complete U.S. Newspaper Directory which lists all the newspapers published from 1690 by state and title and also contains information about repository holdings (who has what)
This project, sponsored by the National Endowment for the Humanities, is a big deal (as best I an tell, it is attempting to scan many more pre-1922 papers than the private company Newsbank has already done). This makes all kinds of historical and genealogical research much more feasible (note this pay-to-play site just launched by genealogy.com as well), and opportunities for all manner of creative history projects abound! And who isn't a little interested in the cartoons, funnies and advertisements from long ago?
Regarding newspapers that are currently under copyright protection (this would be post-1922 in the United States unless they have relinquished those rights), there are a few papers that offer their archives for free on the web and many of these can be found on this Wikipedia page (which covers papers worldwide). Google has indexed many of these and they can be searched via their Google News site. Some have been digitized and others not.
For access to comprehensive runs of the best-known U.S. newspapers from 1922 and up in digitized form, one must look to ProQuest Historical Newspapers. This database is the only place all of these papers can be consulted at once and its access fees run into the thousands of dollars. In reviewing the source, Dr James Mussell says “Given the cost of producing a digital resource on this scale, especially one that republishes content that is still in copyright, we can be sure that ProQuest know their market.”**
Looking to Minnesota in particular, you can get links to every state newspaper from the Minnesota Newspapers Directory site. If you want to do research in the state's historical papers, you won't want to rely on keyword searching alone (made more imperfect by the limitations of Optical Character Recognition [OCR] scanning) but will want the help of the available newspaper subject indexes at the University of Minnesota as well.
*And the Minneapolis Tribune from 1867-1922
**Dr James Mussell, review of ProQuest Historical Newspapers, (review no. 1096) ; URL: http://www.history.ac.uk/reviews/review/1096 ; Date accessed: 14 March, 2013
Image credit: http://nhdarchives.pbworks.com/f/1349103580/NHD%20and%20Chronicling%20America.jpg