If you are seeking copyright protection in California, one of your concerns may be how long that protection will last. This is a good question since other intellectual property protections generally have a specific number of years they are valid, which often are not going to last your lifetime. However, copyright protection terms work a bit differently, according to the U.S. Copyright Office.
The rules for copyrights were changed in 1978, so there are two distinct groups of copyrights with two distinct rules about protection length. Anything created and copyrighted before January 1, 1978 follows a complex set of rules based on exactly when the copyright was secured. This is due to various changes within the laws prior to 1978. First, there was the 1909 Act, which provided a 28-year term of protection with the option to renew for another 28 years of protection. When changes were made in 1978, those works still under protection under the 1909 Act were given an extension of protection for another 67 years. The total length of protection was then 95 years. These guidelines are no longer a concern for works published before January 1, 1923 because they are no longer are protected. However, they are important for those works published after that date and before January 1, 1978.
For those works published in 1978 and later, copyright lasts the life of the author plus 70 years. If the author is unknown, the term of protection is 120 years from creation or 95 years from publication. It is the shorter of the two. There are also no renewal requirements anymore. Once a work is published, you hold the copyright for the complete term. This information is only intended to educate and should not be interpreted as legal advice.