鉄道郵便局
The Railway Mail Association (RMA) was originally "The National Association of Railway Postal Clerks" when chartered under the laws of New Hampshire in 1898 as a fraternal beneficiary association. In 1904 the name was changed to the RMA and lasted until 1949 when the Post Office Department renamed the Railway Mail Service as Postal Transportation Service. At that time, it became the National Postal Transport Association.