Includes digitized print books (18th - 19th century), historical maps and aerial photos, content ready for text mining projects, and more.

Library of Congress's far ranging collection of blueprints, maps, newspapers, graphics, interviews, and videos.

An online library of free eBooks including primary sources.

HathiTrust is a partnership of academic & research institutions, offering a collection of millions of titles digitized from libraries around the world. The HathiTrust Digital Library brings together the immense collections of partner institutions in digital form.

A non-profit library of millions of free books, movies, software, music, websites, and more.

A living database with new materials added every day, featuring prints, photographs, maps, manuscripts, streaming video, and more.

Copyright-free images. Use the Flickr URL in your timeline spreadsheets.

Creative Commons Search is a tool that allows openly licensed and public domain works to be discovered and used by everyone (Creative Commons).

Pixabay is a vibrant community of creatives, sharing copyright free images and videos. All contents are released under the Pixabay License, which makes them safe to use without asking for permission or giving credit to the artist - even for commercial purposes (Pixabay).

The internet’s source of freely-usable images. Unsplash allows photographers to upload photos to its website, which are then curated by a team of photo editors (Wikipedia).