In October 1969 Charley Kline was asked to arrange the first computer-to-computer message through an ordinary telephone line. Working as a programmer in the UCLA lab of Leonard Kleinrock, he was part of a project attempting to connect to the only other existing Internet node located at Stanford University. After establishing the connection, Kline started by typing "login." He typed l and got the echo from Stanford conforming that the letter had been received. He proceeded with o and again received the appropriate echo. Then he ventured to g. However, that was too much for the young system to absorb, and the computer crashed, killing the connection as well.

-- from Linked: The New Science of Networks.