On October 29th 1969, two computers connected to form the ARPANET and launch the world's first successful packet-switched wide area computer network. This first connection, in the form of a logon request, was sent to SRI International (then known as Stanford Research Institute) from the University of California, Los Angeles (UCLA). This remote access initiated a new, flexibly formed network structure for computer resource sharing. While not yet an internet, it did lay critical groundwork for the subsequent Internet and the dramatic changes in how we conduct business, communicate, socialize, learn, distribute knowledge, and travel. Internetworking began in 1977, when SRI also played a pivotal role in the first known connection of three dissimilar networks.

 

The U.S. Department of Defense Advanced Research Projects Agency (DARPA, then
known as ARPA) began the work that led to the ARPANET in the mid 1960s. A major
goal was to create a reliable computer network with built-in network redundancy
that would provide reliable communications between its major nodes as well as
remote access to these same computing resources, even when the network was
subject to attack.

The initial ARPANET was a network of just four computers located at four
different sites: first UCLA and SRI, followed by the University of California,
Santa Barbara and the University of Utah. By 1972, the ARPANET comprised 37
computers. In the ensuing years it was opened to other research and development
sites including other universities, research contractors, and government labs.
Its usefulness as a platform for the new world of digital communications and
information sharing soon became evident.