The U.S. Postal Inspection Service has been called the “silent service” because, for most of the 20th century, this federal law enforcement and security agency did not seek publicity. However, for as long as there has been a mail system in the United States, there has been an agency in place to fight crimes involving the U.S. Mail, the Post Office Department, and, later, the U.S. Postal Service (USPS).

Postal Inspection Service managers had believed that postal inspectors enjoyed a tactical advantage against criminals because the agency was not part of the cultural lexicon like some of its colleagues, such as the Federal Bureau of Investigation (FBI) and the Secret Service. In the past 20 years, however, the Postal Inspection Service has tried to move away from its reputation as the silent service.