American Periodicals Online Series 
This source includes digitized images of the pages of American magazines and journals published from 1740-1940. Titles range from Benjamin Franklin's
General Magazine and America's first scientific journal,
Medical Repository; popular magazines such as
Vanity Fair and
Ladies' Home Journal; regional and niche publications; and groundbreaking journals like
The Dial,
Puck, and
McClure's.
New York Times Historical Offers full-text, full-image articles from 1851 – 2008 of
The New York Times. The database can be used to search national and international news, editorials, obituaries, birth and marriage announcements, plus historical photos and advertisements. The documents are downloadable in PDF format.
How to export to RefWorks
American Memory: the online collections of the Library of Congress, organized by theme and by period.
Chronicling America: historic American newspapers (1836-1922) at the Library of Congress.
National Archives: - DocsTeach (thousands of historical documents to be used in the classroom)
- Online Public Access search (For an overview of the holdings at NARA, see their Research topics pages)
- Digital Vaults (an interactive exploration of primary sources at the National Archives. Create your own collection and even create posters or movies).
Seeking Michigan: digital collections of the Archives of Michigan (maps, photos, pre-statehood documents, civil war records...)
Internet Archive:
a non-profit digital library offering free universal access to books, movies & music, as well as 150 billion archived web pages. World History Sources: primary sources to support world history teaching.
History Matters list of web resources by topic and period.
Social Explorer: Census data presented in interactive maps. The public edition (free of charge) contains
socio-economic and demographic data from 1790 to 2009.Hathi Trust: Books, journals and more. Works in the public domain are available full text.