Railway Mail Service
As a political spoil, Bangs was appointed postmaster of Aurora in 1861 as one of Lincoln's first appointments, and served – with a reappointment in 1865 – until 1869. He befriended George B. Armstrong, who became the General Superintendent of the Railway Mail Service (RMS) in 1869, at which time Bangs was made the assistant superintendent in Chicago. Upon the retirement of Armstrong in 1871, President Ulysses S. Grant appointed Bangs General Superintendent in Washington, D.C.