If you wish to use a copyrighted work and fair use (or another legal exemption) doesn't seem to apply, you may need to seek permission. Keep in mind that the person who created the work may not be the copyright holder. Below are some online resources to assist with the permissions process.
Orphan works are works protected by copyright for which the author/creator or copyright holder cannot be found. Because the current terms of copyright protection are extensive, many 20th century U.S. works fall into this category. Individuals and groups who would like to use or provide access to orphan works are reluctant to do so because of concerns with being held liable for copyright infringement.