Congress embedded a right to privacy in the mails when it established the United States Postal Service through the Postal Act of 1792. The guarantee of secure mail was exceptional, as many European governments during that time continued to open mail for internal surveillance.

Congress prohibited the surveying of mail. Newspapers were transmitted free from government scrutiny and regardless of their content. Postal officials were prohibited from opening letters. The act allowed secure and unrestrained communication, inspiring a communication revolution in which Americans everywhere could follow and participate freely in national discussions.