ARPANET history: The first internet message sent in 1969

On October 29, 1969, the first message was transmitted between two computers via ARPANET, the precursor to the modern internet. The historic event took place at 10:30 PM local time, connecting a computer at the University of California, Los Angeles (UCLA) to one at the Stanford Research Institute in Menlo Park, California.

Programmer Charley Kline attempted to log in to the remote system by typing the command ‘LOGIN’. However, the system crashed after the first two letters were transmitted. As a result, the very first message sent over the network was simply ‘LO’.

Professor Leonard Kleinrock, who led the UCLA team, noted that while the crash prevented the full command from being sent, the connection was successfully re-established about an hour later. The accidental ‘LO’ message has since taken on symbolic meaning, echoing the English phrase ‘lo and behold’.