 The USPS is often mistaken for a state-owned enterprise or government-owned corporation (e.g., Amtrak) because it operates much like a business.It is, however, an "establishment of the executive branch of the Government of the United States", () as it is controlled by presidential appointees and the postmaster general.As a government agency, it has many special privileges, including sovereign immunity, eminent domain powers, powers to negotiate postal treaties with foreign nations, and an exclusive legal right to deliver first-class and third-class mail.