Post Office airplanes were delivering 14 million letters and
It was the Post Office
and airmail delivery that gave the commercial airlines their true start. In the
early part of the 20th century, the Post Office had used mostly railroads to
transport mail between cities. By 1925, only seven years after the first official airmail  
flight, U.S. Post Office airplanes were delivering 14 million letters and
packages a year and were maintaining regular flight schedules. Airmail appealed
particularly to bankers and other businessmen who regularly began to use it to
move checks and financial documents more quickly, reducing the “float” on
checks and the length of time that funds were idle and unavailable for use.