The development of the electric telegraph greatly changed the way diplomacy was conducted in the 19th century. Until that time information was exchanged at the speed of a sailing ship or a galloping horse. During the 1830s and 1840s, inventors working independently in several countries developed workable electric telegraphs, and these devices quickly superseded other technologies with the same name.
By the mid-nineteenth century, telegraphy had acquired its present definition as a device for converting messages into electric impulses that traveled instantaneously by wire to distant receivers, where they were converted back into readable text. European foreign ministries first used telegraphy during the early 1850s, but it did not become an important tool in the diplomacy of the United States until the completion of a successful transatlantic cable in 1866.
Communications Sped up Dramatically
The most significant characteristic of the telegraph was its speed. Telegrams traveled like lightning across continents and oceans. Even with the additional time required for coding and handling, telegrams were typically available within a few hours of being sent. This speed brought many advantages to policymakers who found that they could respond rapidly to far off crises of whose very existence they would previously have remained ignorant for weeks. But the telegraph also brought disadvantages. The ability to act quickly placed new time pressures upon political leaders, especially since telegraphy could inform newspapers and an expectant public just as swiftly.