By Bruce Kennedy
CNN Interactive

They are two enduring images of America from the 1960s -- one of hope, the other of horror. Both are part of the nation's psyche -- and are the subjects of lawsuits that could change the way historical artifacts are handled.

One of the items in question is Martin Luther King Jr.'s "I Have A Dream" speech, delivered before hundreds of thousands of demonstrators during the 1963 March On Washington. The other took place less than three months later in Dallas.

On November 22 of that year, clothing manufacturer Abraham Zapruder took out his 8mm movie camera to photograph a passing presidential motorcade. Twenty-six seconds of that movie show in painful detail the assassination of President John F. Kennedy. That brief clip has become one of the most closely scrutinized pieces of film in history.

In recent years, the families of both King and Zapruder have gone to court. King's family has argued that the rights to his speech belong to their estate -- and that others should not profit from it. The family has asked an appeals court to rule that the speech is private property and that CBS News -- which used a clip of the speech in a documentary -- should pay for infringing on the copyright. The family also has sued a company that planned to sell images of the civil rights activist on refrigerator magnets.

In the case of the Zapruder film, the Assassination Records Review Board, which was set up by Congress in 1992, said in 1997 that the film was U.S. government property. The government is constitutionally required to compensate for any property it seizes and offered the Zapruder family $1 million. But attorneys for the Zapruders say the movie is worth 30 times that much.

The King and Zapruder legal actions bring into focus the concept of what is now called "intellectual property" -- and the issue of just who owns works, images and concepts that have taken on universal overtones.

"People usually think of intellectual property as patents, trademarks and copyrights, but it really goes beyond that," says Bruce Lehman, a former U.S. assistant secretary of commerce and former commissioner of the U.S. Patent and Trademark Office. He defines intellectual property as "the fruits of the mind."

The intangibility of such work and the difficulties in defining it lead to conflict between those who think such writings, words and images belong to the ages -- and others who consider it property.

"There is, of course, this clash when you have historic works of authorship like the Zapruder film and the Martin Luther King speech -- which are clearly exclusive to the person who created them," says copyright attorney Arthur Levine. "And yet, there is such a huge public interest in those works."

Public interest also extends to celebrities and has sparked legal wrangling over who controls access to some of America's cultural icons. Those power struggles have also led to a concept now known as the "right of publicity."

"If you have ... a personality that has become sufficiently famous, where the public identifies you with it, then that becomes something that constitutes intellectual property," Lehman says.

"The right of publicity doesn't apply to normal people -- but if you're a person, a Madonna or Elvis Presley or Liberace, these are people who developed a very identifiable persona that the public very much identifies with them."

Elvis Presley's persona has become a case in point in the ongoing battle over who controls a larger-than-life image or figure.

"We had quite a bit to do with at least affecting the laws (that defend) the right of publicity," says Jack Soden, president and CEO of Elvis Presley Enterprises (EPE).

"We opened Graceland [in Memphis, Tennessee] in 1982, and there were hucksters selling Elvis T-shirts out of the trunks of their cars. The more you looked at the laws, the more they were muddled. It was self-preservation -- there wasn't another situation like Elvis Presley."

In 1984, after lobbying from EPE's attorneys, the Tennessee Legislature passed the Personal Rights Protection Act -- which states that the rights of publicity survive a person's death and pass on indefinitely to their heirs and executors, so long as continuous use is made of that public persona.

Soden uses the analogy of a person who spends decades building a tire factory. "It doesn't make sense to say that after you die the tire factory is public domain -- that people can come in and start taking tires."

Soden calls the widespread appearance of Elvis impersonators a separate issue "that falls smack dab in the middle of First Amendment, the right to dress up and emulate the performance characteristics [of artists]."

He says his organization's approach to such impersonators is "benign neglect. ... But where it crosses the line, and when we send reminders, is when [an impersonator] puts on a jumpsuit, sunglasses and fake sideburns ... then goes one step further and ... attempts to sell merchandise using Elvis' name instead of his own. But as for his right to dress up as Elvis or Marilyn Monroe for that matter, we'd be the last ones to suggest that that piece of free expression be restrained."

The issue of right of personality was considered in 1998 by the U.S. Supreme Court -- when it rejected an appeal from Robyn Astaire, the widow of movie dance great Fred Astaire, who died in 1987.

She had claimed that her husband's image was used without authorization in a dance-instruction videotape made in 1989. Robyn Astaire had won an earlier, lower court hearing. But that ruling was later overturned by a federal judge -- who agreed with the makers of the video that the 1940s-vintage clips of Astaire dancing were in the public domain.

"Fred knew that people would try to use him without permission, because they did during his lifetime," Mrs. Astaire said in a recent interview. "He was very protective of his persona."

Ironically, Robyn Astaire has come under criticism from some in the entertainment community for her refusal to let clips of Astaire and his famous dance partner, Ginger Rogers, appear in a 1992 television show honoring Rogers. She was also questioned for letting a vacuum cleaner company digitally insert images of its product into an old Astaire clip, making it look like the star was dancing with a Dirt Devil.

"There has been such a depletion of funds trying to fight [unauthorized uses of Fred Astaire's persona] that, every once in a while, I'm forced to replenish them," she said in an interview with Entertainment Law & Finance, an industry newsletter.

As new technologies such as the Internet emerge and become a part of everyday life, more conflicts over intellectual property are expected to arise.

"This tension is going to continue," says Levine. "Obviously, there will be another important work of authorship that has great historic importance ... and an individual will attempt to keep it protected. There are things from the Clinton-Lewinsky matter. Her audio tapes may be entitled to copyright protection. It presents more issues than you and I can talk about."