Most inventions are very old ideas by the time they are turned into a practical product. Some ideas, like flying, are innate in our part-bird genome. Others, like communicating at a distance using magnets, were tried 2000 years ago.
Practical inventions happen after the right MATERIALS and METHODS are in place.** The materials and methods were not developed proactively to enable the invention; they matured for other reasons.
In reading up for the Morse prototype, I noticed that clock mainsprings were apparently hard to buy, but wire and solder were taken for granted. Nobody had to draw his own wire or make his own solder.
Soldering was an ancient part of blacksmithing and metalwork, so it wasn’t the triggering variable.
The earliest experiments with electric telegraphy, around 1720, used miles of wire. This implied mass production and affordable prices.
Looking it up: Hand-made wire was ancient, mainly in jewelry. Production started in the 1500s, solely to be cut into pins and nails. The first manufacturer lost its royal monopoly around 1700, and broader mass production got underway. Woven wire started to gain usage in baskets, fences, and sieves.
At that point the large quantities needed for telegraphy were affordable, so telegraphs were invented.
The METHODS were considerably slower to arrive. Magnet coils had to be wound by hand. In fact hand-winding is still common for unique inductors.
= = = = =
**Footnote: As I’ve noted before, the phonograph was the one BIG exception to this rule. All of the materials and methods and skills were in place, active and commercial, by 1500. Music box makers could have turned their machines into phonographs in a few hours if they had wanted to record sound. For reasons that I still haven’t parsed out, nobody wanted to record sound. The idea or dream simply didn’t exist. Even Edison didn’t want to record sound; he was trying to develop a new way of recording telegraph messages (which wasn’t needed because paper tape was working just fine!) and serendipitously realized that his device could record and replay sound.