Library of Congress http://www.loc.gov Prints, photographs, newspapers, and the American Memory Project .
New York Public Library Digital Gallery http://digitalcollections.nypl.org/
Brooklyn Public Library (includes Brooklyn Daily Eagle) http://www.brooklynpubliclibrary.org/
The Papers of John Jay http://www.columbia.edu/cu/lweb/digital/jay/
Internet Archives at https://archive.org/
NYC Department of Records Photo Gallery (at Municipal Archives). http://www.nyc.gov/html/records/html/archives/archives.shtml
Museum of the City of New York http://collections.mcny.org
U.S. Holocaust Memorial Museum http://www.ushmm.org/