Ancestry
http://www.ancestryclassroom.com
AncestryK12 provides teachers with access to classroom resources, professional learning tools, and Ancestry historical records.
Fold3 provides access to US military records, including the stories, photos and personal documents of the men and women who served.
Newspapers.com is the online home of 216 million+ pages of historical newspapers from 4,400+ newspapers in the United States and more.