The length of your copyright depends on when the work was created, published, and/or registered. Duration also depends on whether the work was created by an individual, more than one individual, or as employee or at the direction of another person or company. For works created by individual authors on or after January 1, 1978, copyright protection begins at the moment of creation and lasts for a period of 70 years after the author's death. In the case of "a joint work” (prepared by two or more authors) the term lasts for 70 years after the last surviving author's death. For works made for hire, and for anonymous and pseudonymous works, copyright protection generally lasts for 95 years from publication or 120 years from creation, whichever is shorter.
For works created before January 1, 1978 (protected under the 1909 Copyright Act), the duration rules are quite different (and much more complex). Duration depends on a number of factors, including whether the work was “published” and whether or not the copyright was renewed. In general, under the 1909 Copyright Act, copyright protection begins with first publication of the work and lasts for a period of 28 years, renewable for an additional term of 28 years, for a total term of protection of 56 years. In 1976, Congress extended the renewal term to 47 years, increasing the total possible term of protection to 75 years. In 1998, Congress again extended the renewal term by an additional 20 years, for total possible term of protection of 95 years from publication.
For works created but not published or registered by January 1, 1978, copyright lasts for a period of 70 years after the author’s death (or at least through December 31, 2002). For works published on or before December 31, 2002, the term of copyright lasts through December 31, 2047.