Early English Books Online is the definitive online collection of early printed works in English, on all subjects, published in the British Isles and America from the 15th through 18th centuries. Digital copies of over 125,000 rare works from before 1700 are discoverable through an interface tailored for early modern scholars.
Subject, title, and author indexes can also be searched using the English Short Title Catalogue (link below) of the British Library.
Below are selected Primary Source databases of interest to English and Literature Studies, but WSU LIbraries has many more. Check out all the databases on the Online Primary Sources Research Guide.
WSU Libraries' Special Collections & University Archives has a number of digital collections, manuscripts, maps, rare books, and more. They are a great resources for university and local history.