When does your life story go into the "public domain"?

Here’s something I’ve been curious about for a while. I often hear of people involved in newsworthy events selling the screen rights to their stories to film or television studios. As I understand it, if I were to write a screenplay about Laci Peterson (not that I’d ever want to, but this is a hypothetical example) I’d need to buy the rights from her family if I ever wanted to sell my script.

Now, if I wanted to write a screenplay about the life of Cleopatra VII then I presume I would not have to bother obtaining any rights since she’s been dead for thousands of years and has no known descendants. As long as the screenplay were original and not an adaptation of some preexisting work still under copyright then I’d be in the clear. I figure this is why Cleo and other well-known figures from ancient times often pop up in movies and TV shows, sometimes for little good reason.

But what about more recent historical people and events? What if I wanted to write a screenplay about Stonewall Jackson, Molly Brown, Wallis Warfield Simpson, or the Romanovs? How long does a person have to be dead before their life story becomes fair game for anyone?

Now, you would not be required to pay the family for the rights to portray her life in a screenplay. Laci Peterson is dead, and under U.S. law, you cannot violate the privacy of dead people.

You can, however, violate the privacy of living persons, namely her friends and family. Without their permission to be portrayed on screen, you would have to rely on already published information, accounts, and quotations from and about the family and friends. And speaking of friends, you could also change the names of living persons, or combine several real people into a composite character.

You can also make a movie about a living person if that person is a celebrity. For example, the recent TV movie about Martha Stewart, which did not have the cooperation of Martha, her ex-husband, or any of her family. The producers relied on an already published unauthorized biography of Martha, which had not been challenged in court as libelous by any of the people written about in the book.