Places to Find Primary Source Material 

Library of Congress American Memory Project
American Treasures of the Library of Congress
Today in History
Ad*Access
National Archives and Records Administration Exhibit Hall
United States Historical Documents (University of Oklahoma)
Berkeley SunSITE Digital Collections
Duke University Rare Book, Manuscript and Special Collections Library
Yahoo!'s Listing of Archives
Yahoo!'s Listing of Digital Library Projects and Collections
Yahoo!'s Listing of Map Libraries and Collections
Archiving Early America