Initially they were used in telegraphy, which developed in the late 1830s and 1840s as the first use of electrical engineering, though teleprinters were not used for telegraphy until 1887 at the earliest.

When was the first teleprinter made?

The technology of sending and receiving written messages made a major advance just before Christmas in 1932 when the UK launched the Teleprinter Exchange.

When was teletype used?

Teletypes in one form or another go back to about 1907. They were used originally as automatic Telegraph and Telegram machines. Teletypes reached their familiar mature form in the 1920s and the ASR33 was announced 1962.