Kudos to the New York Public Library (#NYPL) for mining this vein of gold beneath our feet.
https://www.vice.com/en/article/epzyde/librarians-are-finding-thousands-of-books-no-longer-protected-by-copyright-law

"NYPL has been reviewing the US #Copyright Office’s official…records for [books] whose copyrights haven’t been renewed…The books in question were published between 1923 & 1964, before changes to US copyright law removed the requirement for rights holders to renew their copyrights…Around 65 -75% of rights holders opted not to renew their copyrights."

#PublicDomain
🧵

Librarians Are Finding Thousands Of Books No Longer Protected By Copyright Law

Up to 75 percent of books published before 1964 may now be in the public domain, according to researchers at the New York Public Library.

@petersuber this is really cool