Which institute received the first ARPANET message sent from UCLA in 1969?

The Stanford Research Institute received the first ARPANET message sent from UCLA in 1969.

On October 29, 1969, UCLA student programmer Charley Kline attempted to send the command “login” from an SDS Sigma 7 computer to an SDS 940 computer at Stanford Research Institute, or SRI. SRI programmer Bill Duvall operated the receiving system. The connection ran through the first ARPANET Interface Message Processors.

The initial attempt did not transmit the entire word. After Kline typed “l” and “o,” the SRI computer crashed, so the literal first message successfully sent was “lo.” The machines were adjusted, and roughly an hour later the full login was completed. That event is widely treated as the first successful host-to-host ARPANET connection.

SRI was not a university campus in the usual sense; it was a research institute in Menlo Park, California, formerly connected with Stanford University. This distinction causes occasional confusion in quiz answers. UCLA was the sending site, while SRI was the receiving site. The University of Utah and UC Santa Barbara became two of the other original four ARPANET nodes later in 1969.