What Was the First Message Sent over the Internet?

The Information Age had a somewhat inauspicious beginning. Just three months after man first walked on the Moon, a UCLA professor and a grad student successfully sent a message over ARPANET, one of the world’s first computer networks and the predecessor to the modern Internet, in October 1969. Using a set of primitive routers that connected Leonard Kleinrock and Charley Kline at UCLA with Bill Duvall at Stanford, on phone lines leased from AT&T, the first message was sent. Attempting to transmit the word “login,” a system crash limited the message to just “lo.” An hour later, the entire message was transmitted successfully.

Lo, are you there?

• In 2015, Kleinrock admitted the accidental transmission (“lo”) turned out to be a powerful and prophetic message. Essentially, the meaning of the message sent 350 miles (563 km) up the California coast was “hello.”
• Kline, who was only 21 years old at the time, later said he didn’t think he was making history. “I had no expectation that what I was doing that evening would be particularly significant,” he said.
• The first-ever official email was sent in 1971 by Ray Tomlinson, a computer engineer and programmer for BBN Technologies. By this time, ARPANET connected 15 computers.