If a published item is from 1922 or before, then it is public domain. (U.S. Copyright Oce 1992)
Unpublished items, such as letters or manuscripts, if created before 1978, are protected under a dierent
part of the law. If the unpublished item does not have a known author or is a work made for hire, then its
copyright period is 120 years from the date of creation (For the year 2012, that means 1892 or before). If the
author is known, then the copyright extends to 70 years after their death. For a person who wishes to get
permission to use such an item, they need to nd out when the author died, and the name(s) of the authors
heirs, and then seek permission from them. Doing this type of a search is dicult but not impossible; see the
essay Permissions, Good Faith Eorts, and Disclaimers chapter by Mary Minow for many useful resources.
(Minow 2002b)