Many libraries, museums, and archives have digitized their historic documents and put them online in digital libraries. Here are some large collections (and links to other large collections) you may want to explore.
This map, Map of Battles on Bull Run at Manassas, was created by the Office of the Chief of Engineers in the US War Department. The scanned image comes from the US National Archives via Flickr Commons. The US National Archives has an extensive collection of scanned historical documents and photographs on Flickr.
The web is filled with interesting primary source collections. But how do you find them? You can ask your professor and librarian. You can also try Google. Try searches that combine the term "digital library" with a geographic location or theme. You can also visit the library websites of universities and see if they feature any digital collections.
Do you know of a great, online digital library we should add to this list? Please contact Joan Petit.
The photo on the right, Two 7 Year Old Newsies, circa 1910, is from the US National Archives on Flickr.