The Post Office Department's ultimate goal was to provide coast-to-coast airmail service. By 1918 it had established service between New York and Chicago. After September 8, 1920, airmail was flown across country, from New York to San Francisco. In the early days of airmail service, the lack of ground lighting made night flying impossible.
Mailbags were routinely removed from airplanes at night and placed on mail trains, which sped them on their way. The next morning the bags were put back on the nearest mail airplane to continue their journey. At it's fastest, transcontinental airmail service saved less than 2 days over mail sent the entire distance by train.
To institute coast-to-coast airmail service, postal officials had to show Congress that round-the-clock flying was possible. If mail moved only slightly faster by air than by train, few in Congress would be persuaded to fund the service.
On February 21, 1921, the Post Office Department sent out two planes in each direction, west to east and east to west. The westbound flights turned back in horrible snowstorms. One of the eastbound flights, piloted by William Lewis, crashes near Elko, Nevada. Mail was flown to North Platte, Nebraska, where Jack Knight was scheduled to fly the next segment. Knight ended up flying the mail all the way into Chicago, flying much of the way over unfamiliar ground at night, and in a snowstorm. Knight's remarkable flight captured national attention and helped push for successful funding of airmail service.
Lighting the Way
To save the service, postal officials had to make night flying a reality by providing lighted airways. Carl F. Egge, general superintendent of the Airmail Service, worked with J. V. Magee, an illumination engineer, to organize a viable lighting system along the airmail routes.
Small acetylene gas beacons, visible for 10 miles, were installed at three-mile intervals. Every emergency landing field had a rotating beacon mounted on a 50-foot tower. The beacon made six rotations a minute. Regular landing fields were equipped with high-intensity lamps that dispersed light across the field, and white boundary lights were placed every 150 to 300 feet around the perimeter. Large buildings in the area were floodlighted, and nearby high-rise obstacles were equipped with red lights.