The current copyright holder must first be determined.
This can be determined by searching the US Copyright Office’s public catalog located here.
This can also be determined by simply viewing the credits/publishing information on the copyrighted work itself.
Once the current copyright holder has been determined, the holder must be contacted directly with a request for use of the copyrighted material.
The USCO catalog will provide the copyright holder, but not contact information. Additional searches and research will be required to obtain specific contact information.
If permission is granted, a copy of the correspondence allowing use must be provided as proof.