Post was transported over water in the United States in the later nineteenth and the twentieth century. Route agents and, later, railway post office (RPO)...

In Canada and the United States, a railway post office, commonly abbreviated as RPO, was a railroad car that was normally operated in passenger service...

The United States Postal Service (USPS), also known as the Post Office, U.S. Mail, or Postal Service, is an independent agency of the executive branch...

Publication 59: Abbreviations for Use with ZIP Code, three months after the Post Office introduced ZIP codes in July 1963. The purpose, rather than to standardize...

"To establish Post Offices and post Roads." The Post Office has the constitutional authority to designate mail routes. The Post Office is also empowered...

points. Terminal railway post offices operated generally from 1913-1914 into the mid-1960s, before their function was absorbed by post office sectional centers...

to service. Transport portal Michigan portal Philately portal Boat railway post office – Over-water postal service in the US Mail jumping – Type of mail...

to 1971, the postmaster general was the head of the Post Office Department (or simply "Post Office" until the 1820s.: 60–65 ) and was a member of the president's...

The Post Office Act (17 Stat. 283, enacted June 8, 1872) formally incorporated the United States Post Office Department into the Cabinet of the United...

The Railway Mail Service of the United States Post Office Department was a significant mail transportation service in the US from the mid-19th century...