Hey thanks for the word of warning! I actually did quite a bit of research and you would have been right until 2014, it is now public domain thankfully
http://hyperallergic.com/101079/hap...ats-leaving-copyright-behind-in-the-new-year/
http://blog.librarylaw.com/librarylaw/2006/03/the_tale_of_one.html
Public Domain?
Peter's excellent copyright chart shows that works published in the United States before 1923 are in the public domain. The earliest definite authorized edition of The Tale of Peter Rabbit was published in the United States in 1904. (Also, U.S. copyright status was muddled for the Tale of Peter Rabbit in the United States because Warne failed to properly register a copyright, leading to many pirated versions by 1904. For more, see either of Leslie Linder’s books, A History of the Writings of Beatrix Potter or The History of The Tale of Peter Rabbit, both published by Warne.)
Not all of Potter's well-known twenty-three stories are in the public domain in the United States. The Tale of Little Pig Robinson (published 1930) is protected by copyright and definitely not in the public domain. Two other tales are most likely in the public domain: Cecily Parsley's Nursery Rhymes (the New York Public Library has a US edition published in 1922) and Appley Dapply's Nursery Rhymes (I confirmed via library staff that the University of Illinois has a US edition published in 1917).
Also the website that I get these images from deals exclusively in public domain material, if it is not public domain and verified as such, they will not make ti available.