The Internet Archive Text and Ebook collection includes materials from many different contributors and library/museum systems. Not all collections are public domain or openly licensed.
Hathitrust has partnered with institutions around the world to collect scanned books. Many of the books in the collection are in the public domain. Individual copyright status for each book will be indicated.
Newspapers digitized by the Library of Congress. All the newspapers are printed before 1923, and the LOC presumes that they are in the public domain. Individual use should still be assessed on a case by case basis.
The Library of Congress has made many of their manuscript collections accessible to view for free online. Check rights or permissions information for individual collections.
Questions?
Feel free to ask your Personal Librarian, or you can reach out to Mandi Goodsett, CSU's librarian with a specialization in copyright.