Not only are early incarnations of Mickey Mouse no longer covered by copyright, but as of 1 January last, neither is Popeye (King Features page | Popeye.com | wikipedia), at least in the EU. According to The Times:
Popeye the Sailor copyright free 70 years after Elzie Segar’s death
“I yam what I yam,” declared Popeye. And just what that is is likely to become less clear as the copyright expires on the character who generates about £1.5 billion in annual sales.
From January 1, the iconic sailor falls into the public domain in Britain under an EU law that restricts the rights of authors to 70 years after their death. Elzie Segar, the Illinois artist who created Popeye, his love interest Olive Oyl and nemesis Bluto, died in 1938. .. The copyright expiry means that … anyone can print and sell Popeye posters, T-shirts and even create new comic strips, without the need for authorisation or to make royalty payments. …
… the question of whether any company can now attach Popeye’s famous face to their spinach cans will have to be tested in court.
While the copyright is about to expire inside the EU, the character is protected in the US until 2024. US law protects a work for 95 years after its initial copyright.
The Popeye trademark, a separate entity to Segar’s authorial copyright, is owned by King Features, a subsidiary of the Hearst Corporation which is expected to protect its brand aggressively. …
Moreover, Likelihood of Confusion predicts that the US Congress might be persuaded yet again to extend that copyright period (though there must surely be limits to the US Supreme Court’s forbearance in this matter). In the meantime, as Techdirt (hat tip Peter Black) observes, “what happens with Popeye in the UK may be a rough guide as to what will happen should Mickey Mouse hit the public domain”.
Bonus link: An Informal Rant About [Copyright] Formalities (hat tip: Madisonian).