The first ARPANET message traveled between two computers in 1969.
On October 29, 1969, UCLA student programmer Charley Kline attempted to send the word “LOGIN” to a computer at the Stanford Research Institute. The receiving system crashed after the first two letters, so the first transmitted message was simply “LO.” The full word was sent later after the problem was fixed.
ARPANET was funded by the U.S. Advanced Research Projects Agency, later known as DARPA. Its initial network linked UCLA, the Stanford Research Institute, UC Santa Barbara, and the University of Utah. Packet switching allowed data to be divided into small units and routed through a network.
ARPANET was not the entire modern Internet, but it established important networking concepts and eventually adopted the TCP/IP protocol suite. Its legacy helped shape today’s interconnected global Internet.