These are a few online resources that are open access -- that is, information that is distributed online, free of cost or other barriers. As always, make sure you cite your sources and give credit.
DPLA (Digital Public Library of America) connects people to the riches held within America’s libraries, archives, museums, and other cultural heritage institutions. All of the materials found through DPLA—photographs, books, maps, news footage, oral histories, personal letters, museum objects, artwork, government documents, and so much more—are free and immediately available in digital format.
The Europeana Collections provide access to over 50 million digitised items – books, music, artworks and more – with sophisticated search and filter tools to help you find what you’re looking for.
Their dedicated thematic collections on art, fashion, music, photography and World War I contain galleries, blogs and exhibitions to inform and inspire.
HathiTrust is a partnership of academic & research institutions, offering a collection of millions of titles digitized from libraries around the world. If you are looking for book texts to accompany your project, this is the site to check out!
The Internet Archive a 501(c)(3) non-profit, is building a digital library of Internet sites and other cultural artifacts in digital form. Like a paper library, the Internet Archive provides free access to researchers, historians, scholars, the print disabled, and the general public.
The Internet Archive began in 1996 by archiving the Internet itself, a medium that was just beginning to grow in use. Like newspapers, the content published on the web was ephemeral - but unlike newspapers, no one was saving it. Today it has 20+ years of web history accessible through the Wayback Machine and they work with 450+ library and other partners through our Archive-It program to identify important web pages.