Title 39 of the U.S. Code is devoted to the U.S. Postal Service (USPS). Most laws on the USPS can be found there, though some postal laws also may be found in Title 18, and other references to the “postal service” may be found throughout the U.S. Code.
Research Note: The Laws That Established and Govern the U.S. Postal Service
May 22, 2009