The search engine on the left is a google custom search, designed to return primary sources from free online collections. You can explore them individually at the following locations:
American Memory (Library of Congress) written and spoken words, sound recordings, still and moving images, prints, maps, and sheet music that document the American experience
Avalon Project - Documents in Law History and Diplomacy
Chronicling America - Historic American newspapers from 1836 - 1922.
Eurodocs - Links connect to European primary historical documents that are transcribed, reproduced in facsimile, or translated. Also includes some video and sound files, maps, photographs or other imagery, databases, and other documentation.
Hanover Historical Texts - Digital versions of historical texts for use in history and humanities courses.
Internet History Sourcebooks Project - Collection of public domain and copy-permitted historical texts.