U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature.
House & Senate Documents and Reports also includes the pre-1817 American State Papers. In addition many executive branch materials historical maps illustrations etc.
Nineteenth century primary source collections; includes monographs, newspapers, pamphlets, manuscripts, ephemera, maps, statistics and more
U.S. Government publications
Books and other materials in libraries worldwide
GEOSCAN is the bibliographic database for scientific publications of the Earth Sciences Sector (ESS) of Natural Resources Canada.
"HathiTrust is a partnership of academic & research institutions, offering a collection of millions of titles digitized from libraries around the world."--HathiTrust Website
Declassified government documents central to U.S. foreign policy, intelligence, and security since 1945.
Materials relating to all aspects of agriculture forestry and animal science.