In less than two years, the first animated short featuring the character of Mickey Mouse will fall into the public domain, and Disney will no longer be able to prevent other artists or companies from using the character's likeness under U.S. copyright law. Of course, this assumes that nothing changes between now and January 1, 2024, when the character is currently scheduled to become public domain. In the past, Disney has lobbied aggressively to change copyright laws in order to benefit them and other corporations that hold copyrights nearing their natural expiration date. So far, it does not appear there are any major changes coming to U.S. copyright law -- and if not, it could signal a major change.
Mickey's first appearance was in the 1928 animated short "Steamboat Willie," which will lapse into the public domain at the end of 2023, 95 years after its first release. In the short, Mickey looks more or less like he does now, excepting that he wore a hat (since he was conducting a steamboat) and had fewer details than seen in more recent images.
Mickey actually appeared in another short, "Hungry Hobos," which was produced before "Steamboat Willie," but never released, lost, and only found again in 2011, per The Daily Mail.
When Winnie-the-Pooh became a public domain character earlier this year, experts advised caution: characters and material created after the initial book's release can be (and are) still protected by copyright, including characters like Tigger, who appeared in later books. The distinct Disney version of Pooh, which was stylized and did not look identical to the one in A.A. Milne's original stories, is also protected by Disney's trademark.
When "Steamboat Willie" was first released, the copyright term in the United States was 56 years. Disney and others successfully lobbied for the Copyright Act of 1976, which extended protection to 75 years in most cases, while allowing authors who had sold their rights to petition for their return after the initial 56 years. In 1998, Disney lobbied for a further extension, pushing the public domain term out to 95 years. This effectively means that no author will outlive the copyright on their work...but mega-corporations like Disney and Warner Bros. hope to live forever, so they are always hoping for additional protection.
Given the deep pockets of Disney and the importance of Mickey Mouse to their brand, the House of Mouse has consistently been the tip of the spear when it comes to copyright fights. If the laws do not change before "Steamboat Willie" becomes public domain, it's a possible signal that Disney is done dumping money into such lobbying efforts, which would significantly increase the likelihood that characters like Superman and Batman will enter the public domain in the years to come.