Josh Schiller is an associate in the New York offices of Boies Schiller & Flexner who has represented plaintiffs and defendants in copyright infringement lawsuits.

Fifty years ago this week, the Rev. Martin Luther King Jr. delivered his famous “I have a dream” speech. But in coverage of events celebrating its anniversary, the entirety of King’s address will rarely be reprinted, if at all, nor will viewers see footage of his speech delivered in full.

A few months after King delivered the speech, he sent a copy of the address to the U.S. Copyright office and listed the remarks as a “work not reproduced for sale.” In legal terms, this is also known as an unpublished work. He subsequently sued to enjoin two publishers from distributing phonographic reproductions of the address. One of the defendants, 20th Century Fox, had filmed and broadcast all of the speeches at the March on Washington at the request of the march’s organizers. From that material, it had reproduced the phonographs that were the subject of the injunction. But a court ruled that, although King had addressed a large public audience in an unrestricted public forum, reproduction without authorization was an infringement of King’s copyright. Performance of the speech, like the performance of a song or play in a public space, did not create a general waiver of King’s right to limit reproduction under the 1909 Copyright Act.

Since 1963, King and, posthumously, his estate have strictly enforced control over use of that speech and King’s likeness. A few years ago, the estate received more than $700,000from the nonprofit foundation that created and built the monument to King on the Mall in order to use his words and image. The only legal way to reproduce King’s work — at least until it enters the public domain in 2038 — is to pay for a licensing fee, rates for which vary. (Individuals visiting the King Center can buy a recording of the “I have a dream” speech for $20. Licenses for media outlets run into the thousands.)

Although it has been the subject of at least two lawsuits — the King estate sued CBS and USA Today for their use of the speech, reaching undisclosed settlements — a court has never examined whether and under what circumstances the “I have a dream” speech may be used without authorization in what’s considered a “fair use” exception.

Courts look at four factors for fair use: (1) the purpose and character of the use, including whether such use is for commercial or for nonprofit educational purposes; (2) the nature of the copyrighted work; (3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and (4) the effect of the use upon the potential market for or value of the copyrighted work. There are no bright-line rules for fair use; each case must be examined on its facts. Courts have frequently recognized that fair use is central to the “progress of science and advancement of the useful arts” that is the principal tenet upon which copyright laws were created.

Recent jurisprudence has focused on the first and fourth factors, looking primarily at whether the secondary work that cites the material is “transformative.” The threshold is whether the copyrighted material is used as an element, or ingredient, of a new work created for a different purpose and a different audience and whether a new aesthetic or further expression can be perceived by a reasonable observer.

In an important case in 2006, the U.S. Court of Appeals for the 2nd Circuit found that a biographer of the Grateful Dead had made fair use of copyrighted concert posters and tickets whose illustrations are the instantly recognizable sort that observers associate with the band and the 1960s and ’70s. The appropriated images “serve as historical artifacts graphically representing the fact of significant Grateful Dead concert events selected” by the author, the court said, and this use did not harm the first creator’s economic incentives.

Playing a recording of King’s speech as thousands march on the Mall, as happened this past weekend, is surely the sort of non-commercial, educational and historical use that Congress and the courts have frequently and rightly protected.

One can imagine many transformative uses of the “I have a dream” speech — from posting it in social media platforms for people to share and remark upon, to quoting the text in song lyrics or in a film, documentary or other artistic work to conjure the strivings for social equality that were the essence of King’s speech and to celebrate a sense of shared accomplishment that followed.

As an attorney, I believe in respect for the law and observing copyright restrictions. But when it comes to observing the anniversary of such a public moment, one hopes that fair use will allow current generations to appreciate what happened 50 years ago this week and why it was such a moment in American history.

The public benefit of access to historical artifacts such as King’s speech is undeniable. Any restriction on public access to the content of such a historical artifact should be enforced with caution.