Wrong icon
I've always believed (and I've written here several times) that the system of registering and naming broadcast stations began with naval beacons and ship-to-shore communications. The legalities and call letters were then gradually transferred to entertainment stations as the latter category grew.
Noticed a
1921 list of all call letters. This gives a different
flavor to my belief. It's not essentially wrong, but the main
purpose of the original stations was not official naval work or general commercial ship-to-shore.
Here's one page of the three-page list of land stations:
See it? The vast majority of those 'American' stations were in Alaska, Hawaii and Philippines, not the US mainland. Most were owned by
fish-packing companies! Alaska was peculiarly rich in radio because it was rich in fisheries.
Broad
casting and
networks turn out to be accidentally literal words.