If you haven't heard about Google's Timeline (beta) product, then you'll want to warp speed ahead to: http://newstimeline.googlelabs.com/
This is one of the best free products developed for the digital kingdom yet! As you can well imagine, the product is more successful for 20th and 21st century news, than it is for the 1800's. Not withstanding, it provides us with public domain sources in a great web 2.0 fashion.
Most of my hits for 1940's & 50's came from TIME magazine or Wikipedia, as that is the search default (and we all know that TIME is a bit more reliable than Wikipedia). However, don't miss the "queries" button on the toolbar which allows you to search some US Newspapers, blogs, & Popular Science.
Students could use this for a "snapshot" in time, primary source reportings on their event, Biography fodder, or to create postcards from history. The possiblilites are endless! '' Best yet, it's free -- a little stimulus for your research program! Pack this into your educational toolbag.