Communication · 1844
Morse code
Dots and dashes over a single wire: 'What hath God wrought' reaches Baltimore.
Samuel Morse and Alfred Vail's code became the standard of telegraphy after the Washington to Baltimore line opened in May 1844. A simple, robust binary-like encoding, it was used by telegraph and radio operators for over 150 years.
What it built on 1
What it led to 1
Related measurements
The dashed line marks when it first worked.
Telegrams sent in the UK Latest: 5.7M telegrams per year (1983) Source: Our World in Data