Newspaper Navigator. Newspaper Navigator is an index of 1.5 million images published in newspapers between 1900 and 1963. You can search Newspaper Navigator by keyword and then narrow your results by date and or the U.S. state in which the newspaper was published. There is a highly detailed tutorial on how to use the LOC's Newspaper Navigator right on its search page.
I gave the Newspaper Navigator a try this afternoon. It's easy to use, but I was a little disappointed in the results. It appears that the results are based on the tags associated with the images in the newspapers as opposed to the words on the pages themselves. For example, I attempted to find items from Maine newspapers related to the Clean Water Act. Not only did that search not yield any results a broader search without the specification of a state didn't yield any results. Likewise, a search for "moose" didn't yield any results.
Applications for Education
The LOC's Newspaper Navigator could be useful if you or your students are conducting a general interest search for historical photographs from newspapers. But if you're searching for something specific about a topic from a historical newspaper, you'll be better served by using the Google Newspaper Archives. Here's a video about how to search the Google Newspaper Archive.