This year brought tons of books, films and other works of art into the Public Domain. This means that anyone can use these works in other projects without asking for permission.
See the following articles for more information:
A Landslide of Classic Art is About to Enter the Public Domain (from the Atlantic)
New Life for Old Classics, as Their Copyrights Run Out (from the New York Times)
12 Great Movies Just Added to the Public Domain (from Vulture.com)
For the First Time in More Than 20 Years, Copyrighted Works Will Enter the Public Domain (from Smithsonian Magazine)
For a longer list of works, see this article from Lifehacker: These 1923 Copyrighted Works Enter the Public Domain in 2019
And for a pretty comprehensive list, check out the Wikipedia article for 2019 in public domain