THE RECORD
What changed
Morse and Vail's Washington–Baltimore line sent a public message in 1844, followed by railway, press and submarine networks.
EVIDENCE
What remains
Instruments, codebooks, logs and telegrams document real use.
WHY IT MATTERS
Why it matters
It accelerated prices, war and disaster news, changing states and markets.
OPEN QUESTION
Where interpretation begins
Multiple systems competed; the phrase speed of light ignores relays and delivery delays.